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postgresql/src/backend/parser/parse_expr.c
Alvaro Herrera 63cc20205c
Simplify transformJsonAggConstructor() API 
There's no need for callers to pass aggregate names so that the function
can resolve them to OIDs, when callers can just pass aggregate OIDs
directly to begin with.
2023-03-30 21:07:24 +02:00

3821 lines
105 KiB
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/*-------------------------------------------------------------------------
*
* parse_expr.c
* handle expressions in parser
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/parser/parse_expr.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "catalog/pg_aggregate.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/optimizer.h"
#include "parser/analyze.h"
#include "parser/parse_agg.h"
#include "parser/parse_clause.h"
#include "parser/parse_coerce.h"
#include "parser/parse_collate.h"
#include "parser/parse_expr.h"
#include "parser/parse_func.h"
#include "parser/parse_oper.h"
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/timestamp.h"
#include "utils/xml.h"
/* GUC parameters */
bool Transform_null_equals = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
static Node *transformParamRef(ParseState *pstate, ParamRef *pref);
static Node *transformAExprOp(ParseState *pstate, A_Expr *a);
static Node *transformAExprOpAny(ParseState *pstate, A_Expr *a);
static Node *transformAExprOpAll(ParseState *pstate, A_Expr *a);
static Node *transformAExprDistinct(ParseState *pstate, A_Expr *a);
static Node *transformAExprNullIf(ParseState *pstate, A_Expr *a);
static Node *transformAExprIn(ParseState *pstate, A_Expr *a);
static Node *transformAExprBetween(ParseState *pstate, A_Expr *a);
static Node *transformBoolExpr(ParseState *pstate, BoolExpr *a);
static Node *transformFuncCall(ParseState *pstate, FuncCall *fn);
static Node *transformMultiAssignRef(ParseState *pstate, MultiAssignRef *maref);
static Node *transformCaseExpr(ParseState *pstate, CaseExpr *c);
static Node *transformSubLink(ParseState *pstate, SubLink *sublink);
static Node *transformArrayExpr(ParseState *pstate, A_ArrayExpr *a,
Oid array_type, Oid element_type, int32 typmod);
static Node *transformRowExpr(ParseState *pstate, RowExpr *r, bool allowDefault);
static Node *transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c);
static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m);
static Node *transformXmlExpr(ParseState *pstate, XmlExpr *x);
static Node *transformXmlSerialize(ParseState *pstate, XmlSerialize *xs);
static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b);
static Node *transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr);
static Node *transformColumnRef(ParseState *pstate, ColumnRef *cref);
static Node *transformWholeRowRef(ParseState *pstate,
ParseNamespaceItem *nsitem,
int sublevels_up, int location);
static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
static Node *transformJsonObjectConstructor(ParseState *pstate,
JsonObjectConstructor *ctor);
static Node *transformJsonArrayConstructor(ParseState *pstate,
JsonArrayConstructor *ctor);
static Node *transformJsonArrayQueryConstructor(ParseState *pstate,
JsonArrayQueryConstructor *ctor);
static Node *transformJsonObjectAgg(ParseState *pstate, JsonObjectAgg *agg);
static Node *transformJsonArrayAgg(ParseState *pstate, JsonArrayAgg *agg);
static Node *make_row_comparison_op(ParseState *pstate, List *opname,
List *largs, List *rargs, int location);
static Node *make_row_distinct_op(ParseState *pstate, List *opname,
RowExpr *lrow, RowExpr *rrow, int location);
static Expr *make_distinct_op(ParseState *pstate, List *opname,
Node *ltree, Node *rtree, int location);
static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
/*
* transformExpr -
* Analyze and transform expressions. Type checking and type casting is
* done here. This processing converts the raw grammar output into
* expression trees with fully determined semantics.
*/
Node *
transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind)
{
Node *result;
ParseExprKind sv_expr_kind;
/* Save and restore identity of expression type we're parsing */
Assert(exprKind != EXPR_KIND_NONE);
sv_expr_kind = pstate->p_expr_kind;
pstate->p_expr_kind = exprKind;
result = transformExprRecurse(pstate, expr);
pstate->p_expr_kind = sv_expr_kind;
return result;
}
static Node *
transformExprRecurse(ParseState *pstate, Node *expr)
{
Node *result;
if (expr == NULL)
return NULL;
/* Guard against stack overflow due to overly complex expressions */
check_stack_depth();
switch (nodeTag(expr))
{
case T_ColumnRef:
result = transformColumnRef(pstate, (ColumnRef *) expr);
break;
case T_ParamRef:
result = transformParamRef(pstate, (ParamRef *) expr);
break;
case T_A_Const:
result = (Node *) make_const(pstate, (A_Const *) expr);
break;
case T_A_Indirection:
result = transformIndirection(pstate, (A_Indirection *) expr);
break;
case T_A_ArrayExpr:
result = transformArrayExpr(pstate, (A_ArrayExpr *) expr,
InvalidOid, InvalidOid, -1);
break;
case T_TypeCast:
result = transformTypeCast(pstate, (TypeCast *) expr);
break;
case T_CollateClause:
result = transformCollateClause(pstate, (CollateClause *) expr);
break;
case T_A_Expr:
{
A_Expr *a = (A_Expr *) expr;
switch (a->kind)
{
case AEXPR_OP:
result = transformAExprOp(pstate, a);
break;
case AEXPR_OP_ANY:
result = transformAExprOpAny(pstate, a);
break;
case AEXPR_OP_ALL:
result = transformAExprOpAll(pstate, a);
break;
case AEXPR_DISTINCT:
case AEXPR_NOT_DISTINCT:
result = transformAExprDistinct(pstate, a);
break;
case AEXPR_NULLIF:
result = transformAExprNullIf(pstate, a);
break;
case AEXPR_IN:
result = transformAExprIn(pstate, a);
break;
case AEXPR_LIKE:
case AEXPR_ILIKE:
case AEXPR_SIMILAR:
/* we can transform these just like AEXPR_OP */
result = transformAExprOp(pstate, a);
break;
case AEXPR_BETWEEN:
case AEXPR_NOT_BETWEEN:
case AEXPR_BETWEEN_SYM:
case AEXPR_NOT_BETWEEN_SYM:
result = transformAExprBetween(pstate, a);
break;
default:
elog(ERROR, "unrecognized A_Expr kind: %d", a->kind);
result = NULL; /* keep compiler quiet */
break;
}
break;
}
case T_BoolExpr:
result = transformBoolExpr(pstate, (BoolExpr *) expr);
break;
case T_FuncCall:
result = transformFuncCall(pstate, (FuncCall *) expr);
break;
case T_MultiAssignRef:
result = transformMultiAssignRef(pstate, (MultiAssignRef *) expr);
break;
case T_GroupingFunc:
result = transformGroupingFunc(pstate, (GroupingFunc *) expr);
break;
case T_NamedArgExpr:
{
NamedArgExpr *na = (NamedArgExpr *) expr;
na->arg = (Expr *) transformExprRecurse(pstate, (Node *) na->arg);
result = expr;
break;
}
case T_SubLink:
result = transformSubLink(pstate, (SubLink *) expr);
break;
case T_CaseExpr:
result = transformCaseExpr(pstate, (CaseExpr *) expr);
break;
case T_RowExpr:
result = transformRowExpr(pstate, (RowExpr *) expr, false);
break;
case T_CoalesceExpr:
result = transformCoalesceExpr(pstate, (CoalesceExpr *) expr);
break;
case T_MinMaxExpr:
result = transformMinMaxExpr(pstate, (MinMaxExpr *) expr);
break;
case T_XmlExpr:
result = transformXmlExpr(pstate, (XmlExpr *) expr);
break;
case T_XmlSerialize:
result = transformXmlSerialize(pstate, (XmlSerialize *) expr);
break;
case T_NullTest:
{
NullTest *n = (NullTest *) expr;
n->arg = (Expr *) transformExprRecurse(pstate, (Node *) n->arg);
/* the argument can be any type, so don't coerce it */
n->argisrow = type_is_rowtype(exprType((Node *) n->arg));
result = expr;
break;
}
case T_BooleanTest:
result = transformBooleanTest(pstate, (BooleanTest *) expr);
break;
case T_CurrentOfExpr:
result = transformCurrentOfExpr(pstate, (CurrentOfExpr *) expr);
break;
/*
* In all places where DEFAULT is legal, the caller should have
* processed it rather than passing it to transformExpr().
*/
case T_SetToDefault:
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("DEFAULT is not allowed in this context"),
parser_errposition(pstate,
((SetToDefault *) expr)->location)));
break;
/*
* CaseTestExpr doesn't require any processing; it is only
* injected into parse trees in a fully-formed state.
*
* Ordinarily we should not see a Var here, but it is convenient
* for transformJoinUsingClause() to create untransformed operator
* trees containing already-transformed Vars. The best
* alternative would be to deconstruct and reconstruct column
* references, which seems expensively pointless. So allow it.
*/
case T_CaseTestExpr:
case T_Var:
{
result = (Node *) expr;
break;
}
case T_JsonObjectConstructor:
result = transformJsonObjectConstructor(pstate, (JsonObjectConstructor *) expr);
break;
case T_JsonArrayConstructor:
result = transformJsonArrayConstructor(pstate, (JsonArrayConstructor *) expr);
break;
case T_JsonArrayQueryConstructor:
result = transformJsonArrayQueryConstructor(pstate, (JsonArrayQueryConstructor *) expr);
break;
case T_JsonObjectAgg:
result = transformJsonObjectAgg(pstate, (JsonObjectAgg *) expr);
break;
case T_JsonArrayAgg:
result = transformJsonArrayAgg(pstate, (JsonArrayAgg *) expr);
break;
default:
/* should not reach here */
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
result = NULL; /* keep compiler quiet */
break;
}
return result;
}
/*
* helper routine for delivering "column does not exist" error message
*
* (Usually we don't have to work this hard, but the general case of field
* selection from an arbitrary node needs it.)
*/
static void
unknown_attribute(ParseState *pstate, Node *relref, const char *attname,
int location)
{
RangeTblEntry *rte;
if (IsA(relref, Var) &&
((Var *) relref)->varattno == InvalidAttrNumber)
{
/* Reference the RTE by alias not by actual table name */
rte = GetRTEByRangeTablePosn(pstate,
((Var *) relref)->varno,
((Var *) relref)->varlevelsup);
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column %s.%s does not exist",
rte->eref->aliasname, attname),
parser_errposition(pstate, location)));
}
else
{
/* Have to do it by reference to the type of the expression */
Oid relTypeId = exprType(relref);
if (ISCOMPLEX(relTypeId))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" not found in data type %s",
attname, format_type_be(relTypeId)),
parser_errposition(pstate, location)));
else if (relTypeId == RECORDOID)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("could not identify column \"%s\" in record data type",
attname),
parser_errposition(pstate, location)));
else
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("column notation .%s applied to type %s, "
"which is not a composite type",
attname, format_type_be(relTypeId)),
parser_errposition(pstate, location)));
}
}
static Node *
transformIndirection(ParseState *pstate, A_Indirection *ind)
{
Node *last_srf = pstate->p_last_srf;
Node *result = transformExprRecurse(pstate, ind->arg);
List *subscripts = NIL;
int location = exprLocation(result);
ListCell *i;
/*
* We have to split any field-selection operations apart from
* subscripting. Adjacent A_Indices nodes have to be treated as a single
* multidimensional subscript operation.
*/
foreach(i, ind->indirection)
{
Node *n = lfirst(i);
if (IsA(n, A_Indices))
subscripts = lappend(subscripts, n);
else if (IsA(n, A_Star))
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("row expansion via \"*\" is not supported here"),
parser_errposition(pstate, location)));
}
else
{
Node *newresult;
Assert(IsA(n, String));
/* process subscripts before this field selection */
if (subscripts)
result = (Node *) transformContainerSubscripts(pstate,
result,
exprType(result),
exprTypmod(result),
subscripts,
false);
subscripts = NIL;
newresult = ParseFuncOrColumn(pstate,
list_make1(n),
list_make1(result),
last_srf,
NULL,
false,
location);
if (newresult == NULL)
unknown_attribute(pstate, result, strVal(n), location);
result = newresult;
}
}
/* process trailing subscripts, if any */
if (subscripts)
result = (Node *) transformContainerSubscripts(pstate,
result,
exprType(result),
exprTypmod(result),
subscripts,
false);
return result;
}
/*
* Transform a ColumnRef.
*
* If you find yourself changing this code, see also ExpandColumnRefStar.
*/
static Node *
transformColumnRef(ParseState *pstate, ColumnRef *cref)
{
Node *node = NULL;
char *nspname = NULL;
char *relname = NULL;
char *colname = NULL;
ParseNamespaceItem *nsitem;
int levels_up;
enum
{
CRERR_NO_COLUMN,
CRERR_NO_RTE,
CRERR_WRONG_DB,
CRERR_TOO_MANY
} crerr = CRERR_NO_COLUMN;
const char *err;
/*
* Check to see if the column reference is in an invalid place within the
* query. We allow column references in most places, except in default
* expressions and partition bound expressions.
*/
err = NULL;
switch (pstate->p_expr_kind)
{
case EXPR_KIND_NONE:
Assert(false); /* can't happen */
break;
case EXPR_KIND_OTHER:
case EXPR_KIND_JOIN_ON:
case EXPR_KIND_JOIN_USING:
case EXPR_KIND_FROM_SUBSELECT:
case EXPR_KIND_FROM_FUNCTION:
case EXPR_KIND_WHERE:
case EXPR_KIND_POLICY:
case EXPR_KIND_HAVING:
case EXPR_KIND_FILTER:
case EXPR_KIND_WINDOW_PARTITION:
case EXPR_KIND_WINDOW_ORDER:
case EXPR_KIND_WINDOW_FRAME_RANGE:
case EXPR_KIND_WINDOW_FRAME_ROWS:
case EXPR_KIND_WINDOW_FRAME_GROUPS:
case EXPR_KIND_SELECT_TARGET:
case EXPR_KIND_INSERT_TARGET:
case EXPR_KIND_UPDATE_SOURCE:
case EXPR_KIND_UPDATE_TARGET:
case EXPR_KIND_MERGE_WHEN:
case EXPR_KIND_GROUP_BY:
case EXPR_KIND_ORDER_BY:
case EXPR_KIND_DISTINCT_ON:
case EXPR_KIND_LIMIT:
case EXPR_KIND_OFFSET:
case EXPR_KIND_RETURNING:
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CHECK_CONSTRAINT:
case EXPR_KIND_DOMAIN_CHECK:
case EXPR_KIND_FUNCTION_DEFAULT:
case EXPR_KIND_INDEX_EXPRESSION:
case EXPR_KIND_INDEX_PREDICATE:
case EXPR_KIND_STATS_EXPRESSION:
case EXPR_KIND_ALTER_COL_TRANSFORM:
case EXPR_KIND_EXECUTE_PARAMETER:
case EXPR_KIND_TRIGGER_WHEN:
case EXPR_KIND_PARTITION_EXPRESSION:
case EXPR_KIND_CALL_ARGUMENT:
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
case EXPR_KIND_CYCLE_MARK:
/* okay */
break;
case EXPR_KIND_COLUMN_DEFAULT:
err = _("cannot use column reference in DEFAULT expression");
break;
case EXPR_KIND_PARTITION_BOUND:
err = _("cannot use column reference in partition bound expression");
break;
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
* extending this switch. If we do see an unrecognized value at
* runtime, the behavior will be the same as for EXPR_KIND_OTHER,
* which is sane anyway.
*/
}
if (err)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg_internal("%s", err),
parser_errposition(pstate, cref->location)));
/*
* Give the PreParseColumnRefHook, if any, first shot. If it returns
* non-null then that's all, folks.
*/
if (pstate->p_pre_columnref_hook != NULL)
{
node = pstate->p_pre_columnref_hook(pstate, cref);
if (node != NULL)
return node;
}
/*----------
* The allowed syntaxes are:
*
* A First try to resolve as unqualified column name;
* if no luck, try to resolve as unqualified table name (A.*).
* A.B A is an unqualified table name; B is either a
* column or function name (trying column name first).
* A.B.C schema A, table B, col or func name C.
* A.B.C.D catalog A, schema B, table C, col or func D.
* A.* A is an unqualified table name; means whole-row value.
* A.B.* whole-row value of table B in schema A.
* A.B.C.* whole-row value of table C in schema B in catalog A.
*
* We do not need to cope with bare "*"; that will only be accepted by
* the grammar at the top level of a SELECT list, and transformTargetList
* will take care of it before it ever gets here. Also, "A.*" etc will
* be expanded by transformTargetList if they appear at SELECT top level,
* so here we are only going to see them as function or operator inputs.
*
* Currently, if a catalog name is given then it must equal the current
* database name; we check it here and then discard it.
*----------
*/
switch (list_length(cref->fields))
{
case 1:
{
Node *field1 = (Node *) linitial(cref->fields);
colname = strVal(field1);
/* Try to identify as an unqualified column */
node = colNameToVar(pstate, colname, false, cref->location);
if (node == NULL)
{
/*
* Not known as a column of any range-table entry.
*
* Try to find the name as a relation. Note that only
* relations already entered into the rangetable will be
* recognized.
*
* This is a hack for backwards compatibility with
* PostQUEL-inspired syntax. The preferred form now is
* "rel.*".
*/
nsitem = refnameNamespaceItem(pstate, NULL, colname,
cref->location,
&levels_up);
if (nsitem)
node = transformWholeRowRef(pstate, nsitem, levels_up,
cref->location);
}
break;
}
case 2:
{
Node *field1 = (Node *) linitial(cref->fields);
Node *field2 = (Node *) lsecond(cref->fields);
relname = strVal(field1);
/* Locate the referenced nsitem */
nsitem = refnameNamespaceItem(pstate, nspname, relname,
cref->location,
&levels_up);
if (nsitem == NULL)
{
crerr = CRERR_NO_RTE;
break;
}
/* Whole-row reference? */
if (IsA(field2, A_Star))
{
node = transformWholeRowRef(pstate, nsitem, levels_up,
cref->location);
break;
}
colname = strVal(field2);
/* Try to identify as a column of the nsitem */
node = scanNSItemForColumn(pstate, nsitem, levels_up, colname,
cref->location);
if (node == NULL)
{
/* Try it as a function call on the whole row */
node = transformWholeRowRef(pstate, nsitem, levels_up,
cref->location);
node = ParseFuncOrColumn(pstate,
list_make1(makeString(colname)),
list_make1(node),
pstate->p_last_srf,
NULL,
false,
cref->location);
}
break;
}
case 3:
{
Node *field1 = (Node *) linitial(cref->fields);
Node *field2 = (Node *) lsecond(cref->fields);
Node *field3 = (Node *) lthird(cref->fields);
nspname = strVal(field1);
relname = strVal(field2);
/* Locate the referenced nsitem */
nsitem = refnameNamespaceItem(pstate, nspname, relname,
cref->location,
&levels_up);
if (nsitem == NULL)
{
crerr = CRERR_NO_RTE;
break;
}
/* Whole-row reference? */
if (IsA(field3, A_Star))
{
node = transformWholeRowRef(pstate, nsitem, levels_up,
cref->location);
break;
}
colname = strVal(field3);
/* Try to identify as a column of the nsitem */
node = scanNSItemForColumn(pstate, nsitem, levels_up, colname,
cref->location);
if (node == NULL)
{
/* Try it as a function call on the whole row */
node = transformWholeRowRef(pstate, nsitem, levels_up,
cref->location);
node = ParseFuncOrColumn(pstate,
list_make1(makeString(colname)),
list_make1(node),
pstate->p_last_srf,
NULL,
false,
cref->location);
}
break;
}
case 4:
{
Node *field1 = (Node *) linitial(cref->fields);
Node *field2 = (Node *) lsecond(cref->fields);
Node *field3 = (Node *) lthird(cref->fields);
Node *field4 = (Node *) lfourth(cref->fields);
char *catname;
catname = strVal(field1);
nspname = strVal(field2);
relname = strVal(field3);
/*
* We check the catalog name and then ignore it.
*/
if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
{
crerr = CRERR_WRONG_DB;
break;
}
/* Locate the referenced nsitem */
nsitem = refnameNamespaceItem(pstate, nspname, relname,
cref->location,
&levels_up);
if (nsitem == NULL)
{
crerr = CRERR_NO_RTE;
break;
}
/* Whole-row reference? */
if (IsA(field4, A_Star))
{
node = transformWholeRowRef(pstate, nsitem, levels_up,
cref->location);
break;
}
colname = strVal(field4);
/* Try to identify as a column of the nsitem */
node = scanNSItemForColumn(pstate, nsitem, levels_up, colname,
cref->location);
if (node == NULL)
{
/* Try it as a function call on the whole row */
node = transformWholeRowRef(pstate, nsitem, levels_up,
cref->location);
node = ParseFuncOrColumn(pstate,
list_make1(makeString(colname)),
list_make1(node),
pstate->p_last_srf,
NULL,
false,
cref->location);
}
break;
}
default:
crerr = CRERR_TOO_MANY; /* too many dotted names */
break;
}
/*
* Now give the PostParseColumnRefHook, if any, a chance. We pass the
* translation-so-far so that it can throw an error if it wishes in the
* case that it has a conflicting interpretation of the ColumnRef. (If it
* just translates anyway, we'll throw an error, because we can't undo
* whatever effects the preceding steps may have had on the pstate.) If it
* returns NULL, use the standard translation, or throw a suitable error
* if there is none.
*/
if (pstate->p_post_columnref_hook != NULL)
{
Node *hookresult;
hookresult = pstate->p_post_columnref_hook(pstate, cref, node);
if (node == NULL)
node = hookresult;
else if (hookresult != NULL)
ereport(ERROR,
(errcode(ERRCODE_AMBIGUOUS_COLUMN),
errmsg("column reference \"%s\" is ambiguous",
NameListToString(cref->fields)),
parser_errposition(pstate, cref->location)));
}
/*
* Throw error if no translation found.
*/
if (node == NULL)
{
switch (crerr)
{
case CRERR_NO_COLUMN:
errorMissingColumn(pstate, relname, colname, cref->location);
break;
case CRERR_NO_RTE:
errorMissingRTE(pstate, makeRangeVar(nspname, relname,
cref->location));
break;
case CRERR_WRONG_DB:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cross-database references are not implemented: %s",
NameListToString(cref->fields)),
parser_errposition(pstate, cref->location)));
break;
case CRERR_TOO_MANY:
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("improper qualified name (too many dotted names): %s",
NameListToString(cref->fields)),
parser_errposition(pstate, cref->location)));
break;
}
}
return node;
}
static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
Node *result;
/*
* The core parser knows nothing about Params. If a hook is supplied,
* call it. If not, or if the hook returns NULL, throw a generic error.
*/
if (pstate->p_paramref_hook != NULL)
result = pstate->p_paramref_hook(pstate, pref);
else
result = NULL;
if (result == NULL)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_PARAMETER),
errmsg("there is no parameter $%d", pref->number),
parser_errposition(pstate, pref->location)));
return result;
}
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
{
if (arg && IsA(arg, A_Const))
{
A_Const *con = (A_Const *) arg;
if (con->isnull)
return true;
}
return false;
}
static Node *
transformAExprOp(ParseState *pstate, A_Expr *a)
{
Node *lexpr = a->lexpr;
Node *rexpr = a->rexpr;
Node *result;
/*
* Special-case "foo = NULL" and "NULL = foo" for compatibility with
* standards-broken products (like Microsoft's). Turn these into IS NULL
* exprs. (If either side is a CaseTestExpr, then the expression was
* generated internally from a CASE-WHEN expression, and
* transform_null_equals does not apply.)
*/
if (Transform_null_equals &&
list_length(a->name) == 1 &&
strcmp(strVal(linitial(a->name)), "=") == 0 &&
(exprIsNullConstant(lexpr) || exprIsNullConstant(rexpr)) &&
(!IsA(lexpr, CaseTestExpr) && !IsA(rexpr, CaseTestExpr)))
{
NullTest *n = makeNode(NullTest);
n->nulltesttype = IS_NULL;
n->location = a->location;
if (exprIsNullConstant(lexpr))
n->arg = (Expr *) rexpr;
else
n->arg = (Expr *) lexpr;
result = transformExprRecurse(pstate, (Node *) n);
}
else if (lexpr && IsA(lexpr, RowExpr) &&
rexpr && IsA(rexpr, SubLink) &&
((SubLink *) rexpr)->subLinkType == EXPR_SUBLINK)
{
/*
* Convert "row op subselect" into a ROWCOMPARE sublink. Formerly the
* grammar did this, but now that a row construct is allowed anywhere
* in expressions, it's easier to do it here.
*/
SubLink *s = (SubLink *) rexpr;
s->subLinkType = ROWCOMPARE_SUBLINK;
s->testexpr = lexpr;
s->operName = a->name;
s->location = a->location;
result = transformExprRecurse(pstate, (Node *) s);
}
else if (lexpr && IsA(lexpr, RowExpr) &&
rexpr && IsA(rexpr, RowExpr))
{
/* ROW() op ROW() is handled specially */
lexpr = transformExprRecurse(pstate, lexpr);
rexpr = transformExprRecurse(pstate, rexpr);
result = make_row_comparison_op(pstate,
a->name,
castNode(RowExpr, lexpr)->args,
castNode(RowExpr, rexpr)->args,
a->location);
}
else
{
/* Ordinary scalar operator */
Node *last_srf = pstate->p_last_srf;
lexpr = transformExprRecurse(pstate, lexpr);
rexpr = transformExprRecurse(pstate, rexpr);
result = (Node *) make_op(pstate,
a->name,
lexpr,
rexpr,
last_srf,
a->location);
}
return result;
}
static Node *
transformAExprOpAny(ParseState *pstate, A_Expr *a)
{
Node *lexpr = transformExprRecurse(pstate, a->lexpr);
Node *rexpr = transformExprRecurse(pstate, a->rexpr);
return (Node *) make_scalar_array_op(pstate,
a->name,
true,
lexpr,
rexpr,
a->location);
}
static Node *
transformAExprOpAll(ParseState *pstate, A_Expr *a)
{
Node *lexpr = transformExprRecurse(pstate, a->lexpr);
Node *rexpr = transformExprRecurse(pstate, a->rexpr);
return (Node *) make_scalar_array_op(pstate,
a->name,
false,
lexpr,
rexpr,
a->location);
}
static Node *
transformAExprDistinct(ParseState *pstate, A_Expr *a)
{
Node *lexpr = a->lexpr;
Node *rexpr = a->rexpr;
Node *result;
/*
* If either input is an undecorated NULL literal, transform to a NullTest
* on the other input. That's simpler to process than a full DistinctExpr,
* and it avoids needing to require that the datatype have an = operator.
*/
if (exprIsNullConstant(rexpr))
return make_nulltest_from_distinct(pstate, a, lexpr);
if (exprIsNullConstant(lexpr))
return make_nulltest_from_distinct(pstate, a, rexpr);
lexpr = transformExprRecurse(pstate, lexpr);
rexpr = transformExprRecurse(pstate, rexpr);
if (lexpr && IsA(lexpr, RowExpr) &&
rexpr && IsA(rexpr, RowExpr))
{
/* ROW() op ROW() is handled specially */
result = make_row_distinct_op(pstate, a->name,
(RowExpr *) lexpr,
(RowExpr *) rexpr,
a->location);
}
else
{
/* Ordinary scalar operator */
result = (Node *) make_distinct_op(pstate,
a->name,
lexpr,
rexpr,
a->location);
}
/*
* If it's NOT DISTINCT, we first build a DistinctExpr and then stick a
* NOT on top.
*/
if (a->kind == AEXPR_NOT_DISTINCT)
result = (Node *) makeBoolExpr(NOT_EXPR,
list_make1(result),
a->location);
return result;
}
static Node *
transformAExprNullIf(ParseState *pstate, A_Expr *a)
{
Node *lexpr = transformExprRecurse(pstate, a->lexpr);
Node *rexpr = transformExprRecurse(pstate, a->rexpr);
OpExpr *result;
result = (OpExpr *) make_op(pstate,
a->name,
lexpr,
rexpr,
pstate->p_last_srf,
a->location);
/*
* The comparison operator itself should yield boolean ...
*/
if (result->opresulttype != BOOLOID)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("NULLIF requires = operator to yield boolean"),
parser_errposition(pstate, a->location)));
if (result->opretset)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
/* translator: %s is name of a SQL construct, eg NULLIF */
errmsg("%s must not return a set", "NULLIF"),
parser_errposition(pstate, a->location)));
/*
* ... but the NullIfExpr will yield the first operand's type.
*/
result->opresulttype = exprType((Node *) linitial(result->args));
/*
* We rely on NullIfExpr and OpExpr being the same struct
*/
NodeSetTag(result, T_NullIfExpr);
return (Node *) result;
}
static Node *
transformAExprIn(ParseState *pstate, A_Expr *a)
{
Node *result = NULL;
Node *lexpr;
List *rexprs;
List *rvars;
List *rnonvars;
bool useOr;
ListCell *l;
/*
* If the operator is <>, combine with AND not OR.
*/
if (strcmp(strVal(linitial(a->name)), "<>") == 0)
useOr = false;
else
useOr = true;
/*
* We try to generate a ScalarArrayOpExpr from IN/NOT IN, but this is only
* possible if there is a suitable array type available. If not, we fall
* back to a boolean condition tree with multiple copies of the lefthand
* expression. Also, any IN-list items that contain Vars are handled as
* separate boolean conditions, because that gives the planner more scope
* for optimization on such clauses.
*
* First step: transform all the inputs, and detect whether any contain
* Vars.
*/
lexpr = transformExprRecurse(pstate, a->lexpr);
rexprs = rvars = rnonvars = NIL;
foreach(l, (List *) a->rexpr)
{
Node *rexpr = transformExprRecurse(pstate, lfirst(l));
rexprs = lappend(rexprs, rexpr);
if (contain_vars_of_level(rexpr, 0))
rvars = lappend(rvars, rexpr);
else
rnonvars = lappend(rnonvars, rexpr);
}
/*
* ScalarArrayOpExpr is only going to be useful if there's more than one
* non-Var righthand item.
*/
if (list_length(rnonvars) > 1)
{
List *allexprs;
Oid scalar_type;
Oid array_type;
/*
* Try to select a common type for the array elements. Note that
* since the LHS' type is first in the list, it will be preferred when
* there is doubt (eg, when all the RHS items are unknown literals).
*
* Note: use list_concat here not lcons, to avoid damaging rnonvars.
*/
allexprs = list_concat(list_make1(lexpr), rnonvars);
scalar_type = select_common_type(pstate, allexprs, NULL, NULL);
/* We have to verify that the selected type actually works */
if (OidIsValid(scalar_type) &&
!verify_common_type(scalar_type, allexprs))
scalar_type = InvalidOid;
/*
* Do we have an array type to use? Aside from the case where there
* isn't one, we don't risk using ScalarArrayOpExpr when the common
* type is RECORD, because the RowExpr comparison logic below can cope
* with some cases of non-identical row types.
*/
if (OidIsValid(scalar_type) && scalar_type != RECORDOID)
array_type = get_array_type(scalar_type);
else
array_type = InvalidOid;
if (array_type != InvalidOid)
{
/*
* OK: coerce all the right-hand non-Var inputs to the common type
* and build an ArrayExpr for them.
*/
List *aexprs;
ArrayExpr *newa;
aexprs = NIL;
foreach(l, rnonvars)
{
Node *rexpr = (Node *) lfirst(l);
rexpr = coerce_to_common_type(pstate, rexpr,
scalar_type,
"IN");
aexprs = lappend(aexprs, rexpr);
}
newa = makeNode(ArrayExpr);
newa->array_typeid = array_type;
/* array_collid will be set by parse_collate.c */
newa->element_typeid = scalar_type;
newa->elements = aexprs;
newa->multidims = false;
newa->location = -1;
result = (Node *) make_scalar_array_op(pstate,
a->name,
useOr,
lexpr,
(Node *) newa,
a->location);
/* Consider only the Vars (if any) in the loop below */
rexprs = rvars;
}
}
/*
* Must do it the hard way, ie, with a boolean expression tree.
*/
foreach(l, rexprs)
{
Node *rexpr = (Node *) lfirst(l);
Node *cmp;
if (IsA(lexpr, RowExpr) &&
IsA(rexpr, RowExpr))
{
/* ROW() op ROW() is handled specially */
cmp = make_row_comparison_op(pstate,
a->name,
copyObject(((RowExpr *) lexpr)->args),
((RowExpr *) rexpr)->args,
a->location);
}
else
{
/* Ordinary scalar operator */
cmp = (Node *) make_op(pstate,
a->name,
copyObject(lexpr),
rexpr,
pstate->p_last_srf,
a->location);
}
cmp = coerce_to_boolean(pstate, cmp, "IN");
if (result == NULL)
result = cmp;
else
result = (Node *) makeBoolExpr(useOr ? OR_EXPR : AND_EXPR,
list_make2(result, cmp),
a->location);
}
return result;
}
static Node *
transformAExprBetween(ParseState *pstate, A_Expr *a)
{
Node *aexpr;
Node *bexpr;
Node *cexpr;
Node *result;
Node *sub1;
Node *sub2;
List *args;
/* Deconstruct A_Expr into three subexprs */
aexpr = a->lexpr;
args = castNode(List, a->rexpr);
Assert(list_length(args) == 2);
bexpr = (Node *) linitial(args);
cexpr = (Node *) lsecond(args);
/*
* Build the equivalent comparison expression. Make copies of
* multiply-referenced subexpressions for safety. (XXX this is really
* wrong since it results in multiple runtime evaluations of what may be
* volatile expressions ...)
*
* Ideally we would not use hard-wired operators here but instead use
* opclasses. However, mixed data types and other issues make this
* difficult:
* http://archives.postgresql.org/pgsql-hackers/2008-08/msg01142.php
*/
switch (a->kind)
{
case AEXPR_BETWEEN:
args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
aexpr, bexpr,
a->location),
makeSimpleA_Expr(AEXPR_OP, "<=",
copyObject(aexpr), cexpr,
a->location));
result = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
break;
case AEXPR_NOT_BETWEEN:
args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
aexpr, bexpr,
a->location),
makeSimpleA_Expr(AEXPR_OP, ">",
copyObject(aexpr), cexpr,
a->location));
result = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
break;
case AEXPR_BETWEEN_SYM:
args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
aexpr, bexpr,
a->location),
makeSimpleA_Expr(AEXPR_OP, "<=",
copyObject(aexpr), cexpr,
a->location));
sub1 = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=",
copyObject(aexpr), copyObject(cexpr),
a->location),
makeSimpleA_Expr(AEXPR_OP, "<=",
copyObject(aexpr), copyObject(bexpr),
a->location));
sub2 = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
args = list_make2(sub1, sub2);
result = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
break;
case AEXPR_NOT_BETWEEN_SYM:
args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
aexpr, bexpr,
a->location),
makeSimpleA_Expr(AEXPR_OP, ">",
copyObject(aexpr), cexpr,
a->location));
sub1 = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<",
copyObject(aexpr), copyObject(cexpr),
a->location),
makeSimpleA_Expr(AEXPR_OP, ">",
copyObject(aexpr), copyObject(bexpr),
a->location));
sub2 = (Node *) makeBoolExpr(OR_EXPR, args, a->location);
args = list_make2(sub1, sub2);
result = (Node *) makeBoolExpr(AND_EXPR, args, a->location);
break;
default:
elog(ERROR, "unrecognized A_Expr kind: %d", a->kind);
result = NULL; /* keep compiler quiet */
break;
}
return transformExprRecurse(pstate, result);
}
static Node *
transformBoolExpr(ParseState *pstate, BoolExpr *a)
{
List *args = NIL;
const char *opname;
ListCell *lc;
switch (a->boolop)
{
case AND_EXPR:
opname = "AND";
break;
case OR_EXPR:
opname = "OR";
break;
case NOT_EXPR:
opname = "NOT";
break;
default:
elog(ERROR, "unrecognized boolop: %d", (int) a->boolop);
opname = NULL; /* keep compiler quiet */
break;
}
foreach(lc, a->args)
{
Node *arg = (Node *) lfirst(lc);
arg = transformExprRecurse(pstate, arg);
arg = coerce_to_boolean(pstate, arg, opname);
args = lappend(args, arg);
}
return (Node *) makeBoolExpr(a->boolop, args, a->location);
}
static Node *
transformFuncCall(ParseState *pstate, FuncCall *fn)
{
Node *last_srf = pstate->p_last_srf;
List *targs;
ListCell *args;
/* Transform the list of arguments ... */
targs = NIL;
foreach(args, fn->args)
{
targs = lappend(targs, transformExprRecurse(pstate,
(Node *) lfirst(args)));
}
/*
* When WITHIN GROUP is used, we treat its ORDER BY expressions as
* additional arguments to the function, for purposes of function lookup
* and argument type coercion. So, transform each such expression and add
* them to the targs list. We don't explicitly mark where each argument
* came from, but ParseFuncOrColumn can tell what's what by reference to
* list_length(fn->agg_order).
*/
if (fn->agg_within_group)
{
Assert(fn->agg_order != NIL);
foreach(args, fn->agg_order)
{
SortBy *arg = (SortBy *) lfirst(args);
targs = lappend(targs, transformExpr(pstate, arg->node,
EXPR_KIND_ORDER_BY));
}
}
/* ... and hand off to ParseFuncOrColumn */
return ParseFuncOrColumn(pstate,
fn->funcname,
targs,
last_srf,
fn,
false,
fn->location);
}
static Node *
transformMultiAssignRef(ParseState *pstate, MultiAssignRef *maref)
{
SubLink *sublink;
RowExpr *rexpr;
Query *qtree;
TargetEntry *tle;
/* We should only see this in first-stage processing of UPDATE tlists */
Assert(pstate->p_expr_kind == EXPR_KIND_UPDATE_SOURCE);
/* We only need to transform the source if this is the first column */
if (maref->colno == 1)
{
/*
* For now, we only allow EXPR SubLinks and RowExprs as the source of
* an UPDATE multiassignment. This is sufficient to cover interesting
* cases; at worst, someone would have to write (SELECT * FROM expr)
* to expand a composite-returning expression of another form.
*/
if (IsA(maref->source, SubLink) &&
((SubLink *) maref->source)->subLinkType == EXPR_SUBLINK)
{
/* Relabel it as a MULTIEXPR_SUBLINK */
sublink = (SubLink *) maref->source;
sublink->subLinkType = MULTIEXPR_SUBLINK;
/* And transform it */
sublink = (SubLink *) transformExprRecurse(pstate,
(Node *) sublink);
qtree = castNode(Query, sublink->subselect);
/* Check subquery returns required number of columns */
if (count_nonjunk_tlist_entries(qtree->targetList) != maref->ncolumns)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("number of columns does not match number of values"),
parser_errposition(pstate, sublink->location)));
/*
* Build a resjunk tlist item containing the MULTIEXPR SubLink,
* and add it to pstate->p_multiassign_exprs, whence it will later
* get appended to the completed targetlist. We needn't worry
* about selecting a resno for it; transformUpdateStmt will do
* that.
*/
tle = makeTargetEntry((Expr *) sublink, 0, NULL, true);
pstate->p_multiassign_exprs = lappend(pstate->p_multiassign_exprs,
tle);
/*
* Assign a unique-within-this-targetlist ID to the MULTIEXPR
* SubLink. We can just use its position in the
* p_multiassign_exprs list.
*/
sublink->subLinkId = list_length(pstate->p_multiassign_exprs);
}
else if (IsA(maref->source, RowExpr))
{
/* Transform the RowExpr, allowing SetToDefault items */
rexpr = (RowExpr *) transformRowExpr(pstate,
(RowExpr *) maref->source,
true);
/* Check it returns required number of columns */
if (list_length(rexpr->args) != maref->ncolumns)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("number of columns does not match number of values"),
parser_errposition(pstate, rexpr->location)));
/*
* Temporarily append it to p_multiassign_exprs, so we can get it
* back when we come back here for additional columns.
*/
tle = makeTargetEntry((Expr *) rexpr, 0, NULL, true);
pstate->p_multiassign_exprs = lappend(pstate->p_multiassign_exprs,
tle);
}
else
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("source for a multiple-column UPDATE item must be a sub-SELECT or ROW() expression"),
parser_errposition(pstate, exprLocation(maref->source))));
}
else
{
/*
* Second or later column in a multiassignment. Re-fetch the
* transformed SubLink or RowExpr, which we assume is still the last
* entry in p_multiassign_exprs.
*/
Assert(pstate->p_multiassign_exprs != NIL);
tle = (TargetEntry *) llast(pstate->p_multiassign_exprs);
}
/*
* Emit the appropriate output expression for the current column
*/
if (IsA(tle->expr, SubLink))
{
Param *param;
sublink = (SubLink *) tle->expr;
Assert(sublink->subLinkType == MULTIEXPR_SUBLINK);
qtree = castNode(Query, sublink->subselect);
/* Build a Param representing the current subquery output column */
tle = (TargetEntry *) list_nth(qtree->targetList, maref->colno - 1);
Assert(!tle->resjunk);
param = makeNode(Param);
param->paramkind = PARAM_MULTIEXPR;
param->paramid = (sublink->subLinkId << 16) | maref->colno;
param->paramtype = exprType((Node *) tle->expr);
param->paramtypmod = exprTypmod((Node *) tle->expr);
param->paramcollid = exprCollation((Node *) tle->expr);
param->location = exprLocation((Node *) tle->expr);
return (Node *) param;
}
if (IsA(tle->expr, RowExpr))
{
Node *result;
rexpr = (RowExpr *) tle->expr;
/* Just extract and return the next element of the RowExpr */
result = (Node *) list_nth(rexpr->args, maref->colno - 1);
/*
* If we're at the last column, delete the RowExpr from
* p_multiassign_exprs; we don't need it anymore, and don't want it in
* the finished UPDATE tlist. We assume this is still the last entry
* in p_multiassign_exprs.
*/
if (maref->colno == maref->ncolumns)
pstate->p_multiassign_exprs =
list_delete_last(pstate->p_multiassign_exprs);
return result;
}
elog(ERROR, "unexpected expr type in multiassign list");
return NULL; /* keep compiler quiet */
}
static Node *
transformCaseExpr(ParseState *pstate, CaseExpr *c)
{
CaseExpr *newc = makeNode(CaseExpr);
Node *last_srf = pstate->p_last_srf;
Node *arg;
CaseTestExpr *placeholder;
List *newargs;
List *resultexprs;
ListCell *l;
Node *defresult;
Oid ptype;
/* transform the test expression, if any */
arg = transformExprRecurse(pstate, (Node *) c->arg);
/* generate placeholder for test expression */
if (arg)
{
/*
* If test expression is an untyped literal, force it to text. We have
* to do something now because we won't be able to do this coercion on
* the placeholder. This is not as flexible as what was done in 7.4
* and before, but it's good enough to handle the sort of silly coding
* commonly seen.
*/
if (exprType(arg) == UNKNOWNOID)
arg = coerce_to_common_type(pstate, arg, TEXTOID, "CASE");
/*
* Run collation assignment on the test expression so that we know
* what collation to mark the placeholder with. In principle we could
* leave it to parse_collate.c to do that later, but propagating the
* result to the CaseTestExpr would be unnecessarily complicated.
*/
assign_expr_collations(pstate, arg);
placeholder = makeNode(CaseTestExpr);
placeholder->typeId = exprType(arg);
placeholder->typeMod = exprTypmod(arg);
placeholder->collation = exprCollation(arg);
}
else
placeholder = NULL;
newc->arg = (Expr *) arg;
/* transform the list of arguments */
newargs = NIL;
resultexprs = NIL;
foreach(l, c->args)
{
CaseWhen *w = lfirst_node(CaseWhen, l);
CaseWhen *neww = makeNode(CaseWhen);
Node *warg;
warg = (Node *) w->expr;
if (placeholder)
{
/* shorthand form was specified, so expand... */
warg = (Node *) makeSimpleA_Expr(AEXPR_OP, "=",
(Node *) placeholder,
warg,
w->location);
}
neww->expr = (Expr *) transformExprRecurse(pstate, warg);
neww->expr = (Expr *) coerce_to_boolean(pstate,
(Node *) neww->expr,
"CASE/WHEN");
warg = (Node *) w->result;
neww->result = (Expr *) transformExprRecurse(pstate, warg);
neww->location = w->location;
newargs = lappend(newargs, neww);
resultexprs = lappend(resultexprs, neww->result);
}
newc->args = newargs;
/* transform the default clause */
defresult = (Node *) c->defresult;
if (defresult == NULL)
{
A_Const *n = makeNode(A_Const);
n->isnull = true;
n->location = -1;
defresult = (Node *) n;
}
newc->defresult = (Expr *) transformExprRecurse(pstate, defresult);
/*
* Note: default result is considered the most significant type in
* determining preferred type. This is how the code worked before, but it
* seems a little bogus to me --- tgl
*/
resultexprs = lcons(newc->defresult, resultexprs);
ptype = select_common_type(pstate, resultexprs, "CASE", NULL);
Assert(OidIsValid(ptype));
newc->casetype = ptype;
/* casecollid will be set by parse_collate.c */
/* Convert default result clause, if necessary */
newc->defresult = (Expr *)
coerce_to_common_type(pstate,
(Node *) newc->defresult,
ptype,
"CASE/ELSE");
/* Convert when-clause results, if necessary */
foreach(l, newc->args)
{
CaseWhen *w = (CaseWhen *) lfirst(l);
w->result = (Expr *)
coerce_to_common_type(pstate,
(Node *) w->result,
ptype,
"CASE/WHEN");
}
/* if any subexpression contained a SRF, complain */
if (pstate->p_last_srf != last_srf)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
/* translator: %s is name of a SQL construct, eg GROUP BY */
errmsg("set-returning functions are not allowed in %s",
"CASE"),
errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
parser_errposition(pstate,
exprLocation(pstate->p_last_srf))));
newc->location = c->location;
return (Node *) newc;
}
static Node *
transformSubLink(ParseState *pstate, SubLink *sublink)
{
Node *result = (Node *) sublink;
Query *qtree;
const char *err;
/*
* Check to see if the sublink is in an invalid place within the query. We
* allow sublinks everywhere in SELECT/INSERT/UPDATE/DELETE/MERGE, but
* generally not in utility statements.
*/
err = NULL;
switch (pstate->p_expr_kind)
{
case EXPR_KIND_NONE:
Assert(false); /* can't happen */
break;
case EXPR_KIND_OTHER:
/* Accept sublink here; caller must throw error if wanted */
break;
case EXPR_KIND_JOIN_ON:
case EXPR_KIND_JOIN_USING:
case EXPR_KIND_FROM_SUBSELECT:
case EXPR_KIND_FROM_FUNCTION:
case EXPR_KIND_WHERE:
case EXPR_KIND_POLICY:
case EXPR_KIND_HAVING:
case EXPR_KIND_FILTER:
case EXPR_KIND_WINDOW_PARTITION:
case EXPR_KIND_WINDOW_ORDER:
case EXPR_KIND_WINDOW_FRAME_RANGE:
case EXPR_KIND_WINDOW_FRAME_ROWS:
case EXPR_KIND_WINDOW_FRAME_GROUPS:
case EXPR_KIND_SELECT_TARGET:
case EXPR_KIND_INSERT_TARGET:
case EXPR_KIND_UPDATE_SOURCE:
case EXPR_KIND_UPDATE_TARGET:
case EXPR_KIND_MERGE_WHEN:
case EXPR_KIND_GROUP_BY:
case EXPR_KIND_ORDER_BY:
case EXPR_KIND_DISTINCT_ON:
case EXPR_KIND_LIMIT:
case EXPR_KIND_OFFSET:
case EXPR_KIND_RETURNING:
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CYCLE_MARK:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
case EXPR_KIND_DOMAIN_CHECK:
err = _("cannot use subquery in check constraint");
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
err = _("cannot use subquery in DEFAULT expression");
break;
case EXPR_KIND_INDEX_EXPRESSION:
err = _("cannot use subquery in index expression");
break;
case EXPR_KIND_INDEX_PREDICATE:
err = _("cannot use subquery in index predicate");
break;
case EXPR_KIND_STATS_EXPRESSION:
err = _("cannot use subquery in statistics expression");
break;
case EXPR_KIND_ALTER_COL_TRANSFORM:
err = _("cannot use subquery in transform expression");
break;
case EXPR_KIND_EXECUTE_PARAMETER:
err = _("cannot use subquery in EXECUTE parameter");
break;
case EXPR_KIND_TRIGGER_WHEN:
err = _("cannot use subquery in trigger WHEN condition");
break;
case EXPR_KIND_PARTITION_BOUND:
err = _("cannot use subquery in partition bound");
break;
case EXPR_KIND_PARTITION_EXPRESSION:
err = _("cannot use subquery in partition key expression");
break;
case EXPR_KIND_CALL_ARGUMENT:
err = _("cannot use subquery in CALL argument");
break;
case EXPR_KIND_COPY_WHERE:
err = _("cannot use subquery in COPY FROM WHERE condition");
break;
case EXPR_KIND_GENERATED_COLUMN:
err = _("cannot use subquery in column generation expression");
break;
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
* extending this switch. If we do see an unrecognized value at
* runtime, the behavior will be the same as for EXPR_KIND_OTHER,
* which is sane anyway.
*/
}
if (err)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg_internal("%s", err),
parser_errposition(pstate, sublink->location)));
pstate->p_hasSubLinks = true;
/*
* OK, let's transform the sub-SELECT.
*/
qtree = parse_sub_analyze(sublink->subselect, pstate, NULL, false, true);
/*
* Check that we got a SELECT. Anything else should be impossible given
* restrictions of the grammar, but check anyway.
*/
if (!IsA(qtree, Query) ||
qtree->commandType != CMD_SELECT)
elog(ERROR, "unexpected non-SELECT command in SubLink");
sublink->subselect = (Node *) qtree;
if (sublink->subLinkType == EXISTS_SUBLINK)
{
/*
* EXISTS needs no test expression or combining operator. These fields
* should be null already, but make sure.
*/
sublink->testexpr = NULL;
sublink->operName = NIL;
}
else if (sublink->subLinkType == EXPR_SUBLINK ||
sublink->subLinkType == ARRAY_SUBLINK)
{
/*
* Make sure the subselect delivers a single column (ignoring resjunk
* targets).
*/
if (count_nonjunk_tlist_entries(qtree->targetList) != 1)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("subquery must return only one column"),
parser_errposition(pstate, sublink->location)));
/*
* EXPR and ARRAY need no test expression or combining operator. These
* fields should be null already, but make sure.
*/
sublink->testexpr = NULL;
sublink->operName = NIL;
}
else if (sublink->subLinkType == MULTIEXPR_SUBLINK)
{
/* Same as EXPR case, except no restriction on number of columns */
sublink->testexpr = NULL;
sublink->operName = NIL;
}
else
{
/* ALL, ANY, or ROWCOMPARE: generate row-comparing expression */
Node *lefthand;
List *left_list;
List *right_list;
ListCell *l;
/*
* If the source was "x IN (select)", convert to "x = ANY (select)".
*/
if (sublink->operName == NIL)
sublink->operName = list_make1(makeString("="));
/*
* Transform lefthand expression, and convert to a list
*/
lefthand = transformExprRecurse(pstate, sublink->testexpr);
if (lefthand && IsA(lefthand, RowExpr))
left_list = ((RowExpr *) lefthand)->args;
else
left_list = list_make1(lefthand);
/*
* Build a list of PARAM_SUBLINK nodes representing the output columns
* of the subquery.
*/
right_list = NIL;
foreach(l, qtree->targetList)
{
TargetEntry *tent = (TargetEntry *) lfirst(l);
Param *param;
if (tent->resjunk)
continue;
param = makeNode(Param);
param->paramkind = PARAM_SUBLINK;
param->paramid = tent->resno;
param->paramtype = exprType((Node *) tent->expr);
param->paramtypmod = exprTypmod((Node *) tent->expr);
param->paramcollid = exprCollation((Node *) tent->expr);
param->location = -1;
right_list = lappend(right_list, param);
}
/*
* We could rely on make_row_comparison_op to complain if the list
* lengths differ, but we prefer to generate a more specific error
* message.
*/
if (list_length(left_list) < list_length(right_list))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("subquery has too many columns"),
parser_errposition(pstate, sublink->location)));
if (list_length(left_list) > list_length(right_list))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("subquery has too few columns"),
parser_errposition(pstate, sublink->location)));
/*
* Identify the combining operator(s) and generate a suitable
* row-comparison expression.
*/
sublink->testexpr = make_row_comparison_op(pstate,
sublink->operName,
left_list,
right_list,
sublink->location);
}
return result;
}
/*
* transformArrayExpr
*
* If the caller specifies the target type, the resulting array will
* be of exactly that type. Otherwise we try to infer a common type
* for the elements using select_common_type().
*/
static Node *
transformArrayExpr(ParseState *pstate, A_ArrayExpr *a,
Oid array_type, Oid element_type, int32 typmod)
{
ArrayExpr *newa = makeNode(ArrayExpr);
List *newelems = NIL;
List *newcoercedelems = NIL;
ListCell *element;
Oid coerce_type;
bool coerce_hard;
/*
* Transform the element expressions
*
* Assume that the array is one-dimensional unless we find an array-type
* element expression.
*/
newa->multidims = false;
foreach(element, a->elements)
{
Node *e = (Node *) lfirst(element);
Node *newe;
/*
* If an element is itself an A_ArrayExpr, recurse directly so that we
* can pass down any target type we were given.
*/
if (IsA(e, A_ArrayExpr))
{
newe = transformArrayExpr(pstate,
(A_ArrayExpr *) e,
array_type,
element_type,
typmod);
/* we certainly have an array here */
Assert(array_type == InvalidOid || array_type == exprType(newe));
newa->multidims = true;
}
else
{
newe = transformExprRecurse(pstate, e);
/*
* Check for sub-array expressions, if we haven't already found
* one.
*/
if (!newa->multidims && type_is_array(exprType(newe)))
newa->multidims = true;
}
newelems = lappend(newelems, newe);
}
/*
* Select a target type for the elements.
*
* If we haven't been given a target array type, we must try to deduce a
* common type based on the types of the individual elements present.
*/
if (OidIsValid(array_type))
{
/* Caller must ensure array_type matches element_type */
Assert(OidIsValid(element_type));
coerce_type = (newa->multidims ? array_type : element_type);
coerce_hard = true;
}
else
{
/* Can't handle an empty array without a target type */
if (newelems == NIL)
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_DATATYPE),
errmsg("cannot determine type of empty array"),
errhint("Explicitly cast to the desired type, "
"for example ARRAY[]::integer[]."),
parser_errposition(pstate, a->location)));
/* Select a common type for the elements */
coerce_type = select_common_type(pstate, newelems, "ARRAY", NULL);
if (newa->multidims)
{
array_type = coerce_type;
element_type = get_element_type(array_type);
if (!OidIsValid(element_type))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("could not find element type for data type %s",
format_type_be(array_type)),
parser_errposition(pstate, a->location)));
}
else
{
element_type = coerce_type;
array_type = get_array_type(element_type);
if (!OidIsValid(array_type))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("could not find array type for data type %s",
format_type_be(element_type)),
parser_errposition(pstate, a->location)));
}
coerce_hard = false;
}
/*
* Coerce elements to target type
*
* If the array has been explicitly cast, then the elements are in turn
* explicitly coerced.
*
* If the array's type was merely derived from the common type of its
* elements, then the elements are implicitly coerced to the common type.
* This is consistent with other uses of select_common_type().
*/
foreach(element, newelems)
{
Node *e = (Node *) lfirst(element);
Node *newe;
if (coerce_hard)
{
newe = coerce_to_target_type(pstate, e,
exprType(e),
coerce_type,
typmod,
COERCION_EXPLICIT,
COERCE_EXPLICIT_CAST,
-1);
if (newe == NULL)
ereport(ERROR,
(errcode(ERRCODE_CANNOT_COERCE),
errmsg("cannot cast type %s to %s",
format_type_be(exprType(e)),
format_type_be(coerce_type)),
parser_errposition(pstate, exprLocation(e))));
}
else
newe = coerce_to_common_type(pstate, e,
coerce_type,
"ARRAY");
newcoercedelems = lappend(newcoercedelems, newe);
}
newa->array_typeid = array_type;
/* array_collid will be set by parse_collate.c */
newa->element_typeid = element_type;
newa->elements = newcoercedelems;
newa->location = a->location;
return (Node *) newa;
}
static Node *
transformRowExpr(ParseState *pstate, RowExpr *r, bool allowDefault)
{
RowExpr *newr;
char fname[16];
int fnum;
newr = makeNode(RowExpr);
/* Transform the field expressions */
newr->args = transformExpressionList(pstate, r->args,
pstate->p_expr_kind, allowDefault);
/* Disallow more columns than will fit in a tuple */
if (list_length(newr->args) > MaxTupleAttributeNumber)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_COLUMNS),
errmsg("ROW expressions can have at most %d entries",
MaxTupleAttributeNumber),
parser_errposition(pstate, r->location)));
/* Barring later casting, we consider the type RECORD */
newr->row_typeid = RECORDOID;
newr->row_format = COERCE_IMPLICIT_CAST;
/* ROW() has anonymous columns, so invent some field names */
newr->colnames = NIL;
for (fnum = 1; fnum <= list_length(newr->args); fnum++)
{
snprintf(fname, sizeof(fname), "f%d", fnum);
newr->colnames = lappend(newr->colnames, makeString(pstrdup(fname)));
}
newr->location = r->location;
return (Node *) newr;
}
static Node *
transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c)
{
CoalesceExpr *newc = makeNode(CoalesceExpr);
Node *last_srf = pstate->p_last_srf;
List *newargs = NIL;
List *newcoercedargs = NIL;
ListCell *args;
foreach(args, c->args)
{
Node *e = (Node *) lfirst(args);
Node *newe;
newe = transformExprRecurse(pstate, e);
newargs = lappend(newargs, newe);
}
newc->coalescetype = select_common_type(pstate, newargs, "COALESCE", NULL);
/* coalescecollid will be set by parse_collate.c */
/* Convert arguments if necessary */
foreach(args, newargs)
{
Node *e = (Node *) lfirst(args);
Node *newe;
newe = coerce_to_common_type(pstate, e,
newc->coalescetype,
"COALESCE");
newcoercedargs = lappend(newcoercedargs, newe);
}
/* if any subexpression contained a SRF, complain */
if (pstate->p_last_srf != last_srf)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
/* translator: %s is name of a SQL construct, eg GROUP BY */
errmsg("set-returning functions are not allowed in %s",
"COALESCE"),
errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
parser_errposition(pstate,
exprLocation(pstate->p_last_srf))));
newc->args = newcoercedargs;
newc->location = c->location;
return (Node *) newc;
}
static Node *
transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m)
{
MinMaxExpr *newm = makeNode(MinMaxExpr);
List *newargs = NIL;
List *newcoercedargs = NIL;
const char *funcname = (m->op == IS_GREATEST) ? "GREATEST" : "LEAST";
ListCell *args;
newm->op = m->op;
foreach(args, m->args)
{
Node *e = (Node *) lfirst(args);
Node *newe;
newe = transformExprRecurse(pstate, e);
newargs = lappend(newargs, newe);
}
newm->minmaxtype = select_common_type(pstate, newargs, funcname, NULL);
/* minmaxcollid and inputcollid will be set by parse_collate.c */
/* Convert arguments if necessary */
foreach(args, newargs)
{
Node *e = (Node *) lfirst(args);
Node *newe;
newe = coerce_to_common_type(pstate, e,
newm->minmaxtype,
funcname);
newcoercedargs = lappend(newcoercedargs, newe);
}
newm->args = newcoercedargs;
newm->location = m->location;
return (Node *) newm;
}
static Node *
transformXmlExpr(ParseState *pstate, XmlExpr *x)
{
XmlExpr *newx;
ListCell *lc;
int i;
newx = makeNode(XmlExpr);
newx->op = x->op;
if (x->name)
newx->name = map_sql_identifier_to_xml_name(x->name, false, false);
else
newx->name = NULL;
newx->xmloption = x->xmloption;
newx->type = XMLOID; /* this just marks the node as transformed */
newx->typmod = -1;
newx->location = x->location;
/*
* gram.y built the named args as a list of ResTarget. Transform each,
* and break the names out as a separate list.
*/
newx->named_args = NIL;
newx->arg_names = NIL;
foreach(lc, x->named_args)
{
ResTarget *r = lfirst_node(ResTarget, lc);
Node *expr;
char *argname;
expr = transformExprRecurse(pstate, r->val);
if (r->name)
argname = map_sql_identifier_to_xml_name(r->name, false, false);
else if (IsA(r->val, ColumnRef))
argname = map_sql_identifier_to_xml_name(FigureColname(r->val),
true, false);
else
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
x->op == IS_XMLELEMENT
? errmsg("unnamed XML attribute value must be a column reference")
: errmsg("unnamed XML element value must be a column reference"),
parser_errposition(pstate, r->location)));
argname = NULL; /* keep compiler quiet */
}
/* reject duplicate argnames in XMLELEMENT only */
if (x->op == IS_XMLELEMENT)
{
ListCell *lc2;
foreach(lc2, newx->arg_names)
{
if (strcmp(argname, strVal(lfirst(lc2))) == 0)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("XML attribute name \"%s\" appears more than once",
argname),
parser_errposition(pstate, r->location)));
}
}
newx->named_args = lappend(newx->named_args, expr);
newx->arg_names = lappend(newx->arg_names, makeString(argname));
}
/* The other arguments are of varying types depending on the function */
newx->args = NIL;
i = 0;
foreach(lc, x->args)
{
Node *e = (Node *) lfirst(lc);
Node *newe;
newe = transformExprRecurse(pstate, e);
switch (x->op)
{
case IS_XMLCONCAT:
newe = coerce_to_specific_type(pstate, newe, XMLOID,
"XMLCONCAT");
break;
case IS_XMLELEMENT:
/* no coercion necessary */
break;
case IS_XMLFOREST:
newe = coerce_to_specific_type(pstate, newe, XMLOID,
"XMLFOREST");
break;
case IS_XMLPARSE:
if (i == 0)
newe = coerce_to_specific_type(pstate, newe, TEXTOID,
"XMLPARSE");
else
newe = coerce_to_boolean(pstate, newe, "XMLPARSE");
break;
case IS_XMLPI:
newe = coerce_to_specific_type(pstate, newe, TEXTOID,
"XMLPI");
break;
case IS_XMLROOT:
if (i == 0)
newe = coerce_to_specific_type(pstate, newe, XMLOID,
"XMLROOT");
else if (i == 1)
newe = coerce_to_specific_type(pstate, newe, TEXTOID,
"XMLROOT");
else
newe = coerce_to_specific_type(pstate, newe, INT4OID,
"XMLROOT");
break;
case IS_XMLSERIALIZE:
/* not handled here */
Assert(false);
break;
case IS_DOCUMENT:
newe = coerce_to_specific_type(pstate, newe, XMLOID,
"IS DOCUMENT");
break;
}
newx->args = lappend(newx->args, newe);
i++;
}
return (Node *) newx;
}
static Node *
transformXmlSerialize(ParseState *pstate, XmlSerialize *xs)
{
Node *result;
XmlExpr *xexpr;
Oid targetType;
int32 targetTypmod;
xexpr = makeNode(XmlExpr);
xexpr->op = IS_XMLSERIALIZE;
xexpr->args = list_make1(coerce_to_specific_type(pstate,
transformExprRecurse(pstate, xs->expr),
XMLOID,
"XMLSERIALIZE"));
typenameTypeIdAndMod(pstate, xs->typeName, &targetType, &targetTypmod);
xexpr->xmloption = xs->xmloption;
xexpr->indent = xs->indent;
xexpr->location = xs->location;
/* We actually only need these to be able to parse back the expression. */
xexpr->type = targetType;
xexpr->typmod = targetTypmod;
/*
* The actual target type is determined this way. SQL allows char and
* varchar as target types. We allow anything that can be cast implicitly
* from text. This way, user-defined text-like data types automatically
* fit in.
*/
result = coerce_to_target_type(pstate, (Node *) xexpr,
TEXTOID, targetType, targetTypmod,
COERCION_IMPLICIT,
COERCE_IMPLICIT_CAST,
-1);
if (result == NULL)
ereport(ERROR,
(errcode(ERRCODE_CANNOT_COERCE),
errmsg("cannot cast XMLSERIALIZE result to %s",
format_type_be(targetType)),
parser_errposition(pstate, xexpr->location)));
return result;
}
static Node *
transformBooleanTest(ParseState *pstate, BooleanTest *b)
{
const char *clausename;
switch (b->booltesttype)
{
case IS_TRUE:
clausename = "IS TRUE";
break;
case IS_NOT_TRUE:
clausename = "IS NOT TRUE";
break;
case IS_FALSE:
clausename = "IS FALSE";
break;
case IS_NOT_FALSE:
clausename = "IS NOT FALSE";
break;
case IS_UNKNOWN:
clausename = "IS UNKNOWN";
break;
case IS_NOT_UNKNOWN:
clausename = "IS NOT UNKNOWN";
break;
default:
elog(ERROR, "unrecognized booltesttype: %d",
(int) b->booltesttype);
clausename = NULL; /* keep compiler quiet */
}
b->arg = (Expr *) transformExprRecurse(pstate, (Node *) b->arg);
b->arg = (Expr *) coerce_to_boolean(pstate,
(Node *) b->arg,
clausename);
return (Node *) b;
}
static Node *
transformCurrentOfExpr(ParseState *pstate, CurrentOfExpr *cexpr)
{
/* CURRENT OF can only appear at top level of UPDATE/DELETE */
Assert(pstate->p_target_nsitem != NULL);
cexpr->cvarno = pstate->p_target_nsitem->p_rtindex;
/*
* Check to see if the cursor name matches a parameter of type REFCURSOR.
* If so, replace the raw name reference with a parameter reference. (This
* is a hack for the convenience of plpgsql.)
*/
if (cexpr->cursor_name != NULL) /* in case already transformed */
{
ColumnRef *cref = makeNode(ColumnRef);
Node *node = NULL;
/* Build an unqualified ColumnRef with the given name */
cref->fields = list_make1(makeString(cexpr->cursor_name));
cref->location = -1;
/* See if there is a translation available from a parser hook */
if (pstate->p_pre_columnref_hook != NULL)
node = pstate->p_pre_columnref_hook(pstate, cref);
if (node == NULL && pstate->p_post_columnref_hook != NULL)
node = pstate->p_post_columnref_hook(pstate, cref, NULL);
/*
* XXX Should we throw an error if we get a translation that isn't a
* refcursor Param? For now it seems best to silently ignore false
* matches.
*/
if (node != NULL && IsA(node, Param))
{
Param *p = (Param *) node;
if (p->paramkind == PARAM_EXTERN &&
p->paramtype == REFCURSOROID)
{
/* Matches, so convert CURRENT OF to a param reference */
cexpr->cursor_name = NULL;
cexpr->cursor_param = p->paramid;
}
}
}
return (Node *) cexpr;
}
/*
* Construct a whole-row reference to represent the notation "relation.*".
*/
static Node *
transformWholeRowRef(ParseState *pstate, ParseNamespaceItem *nsitem,
int sublevels_up, int location)
{
/*
* Build the appropriate referencing node. Normally this can be a
* whole-row Var, but if the nsitem is a JOIN USING alias then it contains
* only a subset of the columns of the underlying join RTE, so that will
* not work. Instead we immediately expand the reference into a RowExpr.
* Since the JOIN USING's common columns are fully determined at this
* point, there seems no harm in expanding it now rather than during
* planning.
*
* Note that if the RTE is a function returning scalar, we create just a
* plain reference to the function value, not a composite containing a
* single column. This is pretty inconsistent at first sight, but it's
* what we've done historically. One argument for it is that "rel" and
* "rel.*" mean the same thing for composite relations, so why not for
* scalar functions...
*/
if (nsitem->p_names == nsitem->p_rte->eref)
{
Var *result;
result = makeWholeRowVar(nsitem->p_rte, nsitem->p_rtindex,
sublevels_up, true);
/* location is not filled in by makeWholeRowVar */
result->location = location;
/* mark Var if it's nulled by any outer joins */
markNullableIfNeeded(pstate, result);
/* mark relation as requiring whole-row SELECT access */
markVarForSelectPriv(pstate, result);
return (Node *) result;
}
else
{
RowExpr *rowexpr;
List *fields;
/*
* We want only as many columns as are listed in p_names->colnames,
* and we should use those names not whatever possibly-aliased names
* are in the RTE. We needn't worry about marking the RTE for SELECT
* access, as the common columns are surely so marked already.
*/
expandRTE(nsitem->p_rte, nsitem->p_rtindex,
sublevels_up, location, false,
NULL, &fields);
rowexpr = makeNode(RowExpr);
rowexpr->args = list_truncate(fields,
list_length(nsitem->p_names->colnames));
rowexpr->row_typeid = RECORDOID;
rowexpr->row_format = COERCE_IMPLICIT_CAST;
rowexpr->colnames = copyObject(nsitem->p_names->colnames);
rowexpr->location = location;
/* XXX we ought to mark the row as possibly nullable */
return (Node *) rowexpr;
}
}
/*
* Handle an explicit CAST construct.
*
* Transform the argument, look up the type name, and apply any necessary
* coercion function(s).
*/
static Node *
transformTypeCast(ParseState *pstate, TypeCast *tc)
{
Node *result;
Node *arg = tc->arg;
Node *expr;
Oid inputType;
Oid targetType;
int32 targetTypmod;
int location;
/* Look up the type name first */
typenameTypeIdAndMod(pstate, tc->typeName, &targetType, &targetTypmod);
/*
* If the subject of the typecast is an ARRAY[] construct and the target
* type is an array type, we invoke transformArrayExpr() directly so that
* we can pass down the type information. This avoids some cases where
* transformArrayExpr() might not infer the correct type. Otherwise, just
* transform the argument normally.
*/
if (IsA(arg, A_ArrayExpr))
{
Oid targetBaseType;
int32 targetBaseTypmod;
Oid elementType;
/*
* If target is a domain over array, work with the base array type
* here. Below, we'll cast the array type to the domain. In the
* usual case that the target is not a domain, the remaining steps
* will be a no-op.
*/
targetBaseTypmod = targetTypmod;
targetBaseType = getBaseTypeAndTypmod(targetType, &targetBaseTypmod);
elementType = get_element_type(targetBaseType);
if (OidIsValid(elementType))
{
expr = transformArrayExpr(pstate,
(A_ArrayExpr *) arg,
targetBaseType,
elementType,
targetBaseTypmod);
}
else
expr = transformExprRecurse(pstate, arg);
}
else
expr = transformExprRecurse(pstate, arg);
inputType = exprType(expr);
if (inputType == InvalidOid)
return expr; /* do nothing if NULL input */
/*
* Location of the coercion is preferentially the location of the :: or
* CAST symbol, but if there is none then use the location of the type
* name (this can happen in TypeName 'string' syntax, for instance).
*/
location = tc->location;
if (location < 0)
location = tc->typeName->location;
result = coerce_to_target_type(pstate, expr, inputType,
targetType, targetTypmod,
COERCION_EXPLICIT,
COERCE_EXPLICIT_CAST,
location);
if (result == NULL)
ereport(ERROR,
(errcode(ERRCODE_CANNOT_COERCE),
errmsg("cannot cast type %s to %s",
format_type_be(inputType),
format_type_be(targetType)),
parser_coercion_errposition(pstate, location, expr)));
return result;
}
/*
* Handle an explicit COLLATE clause.
*
* Transform the argument, and look up the collation name.
*/
static Node *
transformCollateClause(ParseState *pstate, CollateClause *c)
{
CollateExpr *newc;
Oid argtype;
newc = makeNode(CollateExpr);
newc->arg = (Expr *) transformExprRecurse(pstate, c->arg);
argtype = exprType((Node *) newc->arg);
/*
* The unknown type is not collatable, but coerce_type() takes care of it
* separately, so we'll let it go here.
*/
if (!type_is_collatable(argtype) && argtype != UNKNOWNOID)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("collations are not supported by type %s",
format_type_be(argtype)),
parser_errposition(pstate, c->location)));
newc->collOid = LookupCollation(pstate, c->collname, c->location);
newc->location = c->location;
return (Node *) newc;
}
/*
* Transform a "row compare-op row" construct
*
* The inputs are lists of already-transformed expressions.
* As with coerce_type, pstate may be NULL if no special unknown-Param
* processing is wanted.
*
* The output may be a single OpExpr, an AND or OR combination of OpExprs,
* or a RowCompareExpr. In all cases it is guaranteed to return boolean.
* The AND, OR, and RowCompareExpr cases further imply things about the
* behavior of the operators (ie, they behave as =, <>, or < <= > >=).
*/
static Node *
make_row_comparison_op(ParseState *pstate, List *opname,
List *largs, List *rargs, int location)
{
RowCompareExpr *rcexpr;
RowCompareType rctype;
List *opexprs;
List *opnos;
List *opfamilies;
ListCell *l,
*r;
List **opinfo_lists;
Bitmapset *strats;
int nopers;
int i;
nopers = list_length(largs);
if (nopers != list_length(rargs))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("unequal number of entries in row expressions"),
parser_errposition(pstate, location)));
/*
* We can't compare zero-length rows because there is no principled basis
* for figuring out what the operator is.
*/
if (nopers == 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot compare rows of zero length"),
parser_errposition(pstate, location)));
/*
* Identify all the pairwise operators, using make_op so that behavior is
* the same as in the simple scalar case.
*/
opexprs = NIL;
forboth(l, largs, r, rargs)
{
Node *larg = (Node *) lfirst(l);
Node *rarg = (Node *) lfirst(r);
OpExpr *cmp;
cmp = castNode(OpExpr, make_op(pstate, opname, larg, rarg,
pstate->p_last_srf, location));
/*
* We don't use coerce_to_boolean here because we insist on the
* operator yielding boolean directly, not via coercion. If it
* doesn't yield bool it won't be in any index opfamilies...
*/
if (cmp->opresulttype != BOOLOID)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("row comparison operator must yield type boolean, "
"not type %s",
format_type_be(cmp->opresulttype)),
parser_errposition(pstate, location)));
if (expression_returns_set((Node *) cmp))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("row comparison operator must not return a set"),
parser_errposition(pstate, location)));
opexprs = lappend(opexprs, cmp);
}
/*
* If rows are length 1, just return the single operator. In this case we
* don't insist on identifying btree semantics for the operator (but we
* still require it to return boolean).
*/
if (nopers == 1)
return (Node *) linitial(opexprs);
/*
* Now we must determine which row comparison semantics (= <> < <= > >=)
* apply to this set of operators. We look for btree opfamilies
* containing the operators, and see which interpretations (strategy
* numbers) exist for each operator.
*/
opinfo_lists = (List **) palloc(nopers * sizeof(List *));
strats = NULL;
i = 0;
foreach(l, opexprs)
{
Oid opno = ((OpExpr *) lfirst(l))->opno;
Bitmapset *this_strats;
ListCell *j;
opinfo_lists[i] = get_op_btree_interpretation(opno);
/*
* convert strategy numbers into a Bitmapset to make the intersection
* calculation easy.
*/
this_strats = NULL;
foreach(j, opinfo_lists[i])
{
OpBtreeInterpretation *opinfo = lfirst(j);
this_strats = bms_add_member(this_strats, opinfo->strategy);
}
if (i == 0)
strats = this_strats;
else
strats = bms_int_members(strats, this_strats);
i++;
}
/*
* If there are multiple common interpretations, we may use any one of
* them ... this coding arbitrarily picks the lowest btree strategy
* number.
*/
i = bms_next_member(strats, -1);
if (i < 0)
{
/* No common interpretation, so fail */
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("could not determine interpretation of row comparison operator %s",
strVal(llast(opname))),
errhint("Row comparison operators must be associated with btree operator families."),
parser_errposition(pstate, location)));
}
rctype = (RowCompareType) i;
/*
* For = and <> cases, we just combine the pairwise operators with AND or
* OR respectively.
*/
if (rctype == ROWCOMPARE_EQ)
return (Node *) makeBoolExpr(AND_EXPR, opexprs, location);
if (rctype == ROWCOMPARE_NE)
return (Node *) makeBoolExpr(OR_EXPR, opexprs, location);
/*
* Otherwise we need to choose exactly which opfamily to associate with
* each operator.
*/
opfamilies = NIL;
for (i = 0; i < nopers; i++)
{
Oid opfamily = InvalidOid;
ListCell *j;
foreach(j, opinfo_lists[i])
{
OpBtreeInterpretation *opinfo = lfirst(j);
if (opinfo->strategy == rctype)
{
opfamily = opinfo->opfamily_id;
break;
}
}
if (OidIsValid(opfamily))
opfamilies = lappend_oid(opfamilies, opfamily);
else /* should not happen */
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("could not determine interpretation of row comparison operator %s",
strVal(llast(opname))),
errdetail("There are multiple equally-plausible candidates."),
parser_errposition(pstate, location)));
}
/*
* Now deconstruct the OpExprs and create a RowCompareExpr.
*
* Note: can't just reuse the passed largs/rargs lists, because of
* possibility that make_op inserted coercion operations.
*/
opnos = NIL;
largs = NIL;
rargs = NIL;
foreach(l, opexprs)
{
OpExpr *cmp = (OpExpr *) lfirst(l);
opnos = lappend_oid(opnos, cmp->opno);
largs = lappend(largs, linitial(cmp->args));
rargs = lappend(rargs, lsecond(cmp->args));
}
rcexpr = makeNode(RowCompareExpr);
rcexpr->rctype = rctype;
rcexpr->opnos = opnos;
rcexpr->opfamilies = opfamilies;
rcexpr->inputcollids = NIL; /* assign_expr_collations will fix this */
rcexpr->largs = largs;
rcexpr->rargs = rargs;
return (Node *) rcexpr;
}
/*
* Transform a "row IS DISTINCT FROM row" construct
*
* The input RowExprs are already transformed
*/
static Node *
make_row_distinct_op(ParseState *pstate, List *opname,
RowExpr *lrow, RowExpr *rrow,
int location)
{
Node *result = NULL;
List *largs = lrow->args;
List *rargs = rrow->args;
ListCell *l,
*r;
if (list_length(largs) != list_length(rargs))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("unequal number of entries in row expressions"),
parser_errposition(pstate, location)));
forboth(l, largs, r, rargs)
{
Node *larg = (Node *) lfirst(l);
Node *rarg = (Node *) lfirst(r);
Node *cmp;
cmp = (Node *) make_distinct_op(pstate, opname, larg, rarg, location);
if (result == NULL)
result = cmp;
else
result = (Node *) makeBoolExpr(OR_EXPR,
list_make2(result, cmp),
location);
}
if (result == NULL)
{
/* zero-length rows? Generate constant FALSE */
result = makeBoolConst(false, false);
}
return result;
}
/*
* make the node for an IS DISTINCT FROM operator
*/
static Expr *
make_distinct_op(ParseState *pstate, List *opname, Node *ltree, Node *rtree,
int location)
{
Expr *result;
result = make_op(pstate, opname, ltree, rtree,
pstate->p_last_srf, location);
if (((OpExpr *) result)->opresulttype != BOOLOID)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("IS DISTINCT FROM requires = operator to yield boolean"),
parser_errposition(pstate, location)));
if (((OpExpr *) result)->opretset)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
/* translator: %s is name of a SQL construct, eg NULLIF */
errmsg("%s must not return a set", "IS DISTINCT FROM"),
parser_errposition(pstate, location)));
/*
* We rely on DistinctExpr and OpExpr being same struct
*/
NodeSetTag(result, T_DistinctExpr);
return result;
}
/*
* Produce a NullTest node from an IS [NOT] DISTINCT FROM NULL construct
*
* "arg" is the untransformed other argument
*/
static Node *
make_nulltest_from_distinct(ParseState *pstate, A_Expr *distincta, Node *arg)
{
NullTest *nt = makeNode(NullTest);
nt->arg = (Expr *) transformExprRecurse(pstate, arg);
/* the argument can be any type, so don't coerce it */
if (distincta->kind == AEXPR_NOT_DISTINCT)
nt->nulltesttype = IS_NULL;
else
nt->nulltesttype = IS_NOT_NULL;
/* argisrow = false is correct whether or not arg is composite */
nt->argisrow = false;
nt->location = distincta->location;
return (Node *) nt;
}
/*
* Produce a string identifying an expression by kind.
*
* Note: when practical, use a simple SQL keyword for the result. If that
* doesn't work well, check call sites to see whether custom error message
* strings are required.
*/
const char *
ParseExprKindName(ParseExprKind exprKind)
{
switch (exprKind)
{
case EXPR_KIND_NONE:
return "invalid expression context";
case EXPR_KIND_OTHER:
return "extension expression";
case EXPR_KIND_JOIN_ON:
return "JOIN/ON";
case EXPR_KIND_JOIN_USING:
return "JOIN/USING";
case EXPR_KIND_FROM_SUBSELECT:
return "sub-SELECT in FROM";
case EXPR_KIND_FROM_FUNCTION:
return "function in FROM";
case EXPR_KIND_WHERE:
return "WHERE";
case EXPR_KIND_POLICY:
return "POLICY";
case EXPR_KIND_HAVING:
return "HAVING";
case EXPR_KIND_FILTER:
return "FILTER";
case EXPR_KIND_WINDOW_PARTITION:
return "window PARTITION BY";
case EXPR_KIND_WINDOW_ORDER:
return "window ORDER BY";
case EXPR_KIND_WINDOW_FRAME_RANGE:
return "window RANGE";
case EXPR_KIND_WINDOW_FRAME_ROWS:
return "window ROWS";
case EXPR_KIND_WINDOW_FRAME_GROUPS:
return "window GROUPS";
case EXPR_KIND_SELECT_TARGET:
return "SELECT";
case EXPR_KIND_INSERT_TARGET:
return "INSERT";
case EXPR_KIND_UPDATE_SOURCE:
case EXPR_KIND_UPDATE_TARGET:
return "UPDATE";
case EXPR_KIND_MERGE_WHEN:
return "MERGE WHEN";
case EXPR_KIND_GROUP_BY:
return "GROUP BY";
case EXPR_KIND_ORDER_BY:
return "ORDER BY";
case EXPR_KIND_DISTINCT_ON:
return "DISTINCT ON";
case EXPR_KIND_LIMIT:
return "LIMIT";
case EXPR_KIND_OFFSET:
return "OFFSET";
case EXPR_KIND_RETURNING:
return "RETURNING";
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
return "VALUES";
case EXPR_KIND_CHECK_CONSTRAINT:
case EXPR_KIND_DOMAIN_CHECK:
return "CHECK";
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
return "DEFAULT";
case EXPR_KIND_INDEX_EXPRESSION:
return "index expression";
case EXPR_KIND_INDEX_PREDICATE:
return "index predicate";
case EXPR_KIND_STATS_EXPRESSION:
return "statistics expression";
case EXPR_KIND_ALTER_COL_TRANSFORM:
return "USING";
case EXPR_KIND_EXECUTE_PARAMETER:
return "EXECUTE";
case EXPR_KIND_TRIGGER_WHEN:
return "WHEN";
case EXPR_KIND_PARTITION_BOUND:
return "partition bound";
case EXPR_KIND_PARTITION_EXPRESSION:
return "PARTITION BY";
case EXPR_KIND_CALL_ARGUMENT:
return "CALL";
case EXPR_KIND_COPY_WHERE:
return "WHERE";
case EXPR_KIND_GENERATED_COLUMN:
return "GENERATED AS";
case EXPR_KIND_CYCLE_MARK:
return "CYCLE";
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
* extending this switch. If we do see an unrecognized value at
* runtime, we'll fall through to the "unrecognized" return.
*/
}
return "unrecognized expression kind";
}
/*
* Make string Const node from JSON encoding name.
*
* UTF8 is default encoding.
*/
static Const *
getJsonEncodingConst(JsonFormat *format)
{
JsonEncoding encoding;
const char *enc;
Name encname = palloc(sizeof(NameData));
if (!format ||
format->format_type == JS_FORMAT_DEFAULT ||
format->encoding == JS_ENC_DEFAULT)
encoding = JS_ENC_UTF8;
else
encoding = format->encoding;
switch (encoding)
{
case JS_ENC_UTF16:
enc = "UTF16";
break;
case JS_ENC_UTF32:
enc = "UTF32";
break;
case JS_ENC_UTF8:
enc = "UTF8";
break;
default:
elog(ERROR, "invalid JSON encoding: %d", encoding);
break;
}
namestrcpy(encname, enc);
return makeConst(NAMEOID, -1, InvalidOid, NAMEDATALEN,
NameGetDatum(encname), false, false);
}
/*
* Make bytea => text conversion using specified JSON format encoding.
*/
static Node *
makeJsonByteaToTextConversion(Node *expr, JsonFormat *format, int location)
{
Const *encoding = getJsonEncodingConst(format);
FuncExpr *fexpr = makeFuncExpr(F_CONVERT_FROM, TEXTOID,
list_make2(expr, encoding),
InvalidOid, InvalidOid,
COERCE_EXPLICIT_CALL);
fexpr->location = location;
return (Node *) fexpr;
}
/*
* Make a CaseTestExpr node.
*/
static Node *
makeCaseTestExpr(Node *expr)
{
CaseTestExpr *placeholder = makeNode(CaseTestExpr);
placeholder->typeId = exprType(expr);
placeholder->typeMod = exprTypmod(expr);
placeholder->collation = exprCollation(expr);
return (Node *) placeholder;
}
/*
* Transform JSON value expression using specified input JSON format or
* default format otherwise.
*/
static Node *
transformJsonValueExpr(ParseState *pstate, JsonValueExpr *ve,
JsonFormatType default_format)
{
Node *expr = transformExprRecurse(pstate, (Node *) ve->raw_expr);
Node *rawexpr;
JsonFormatType format;
Oid exprtype;
int location;
char typcategory;
bool typispreferred;
/*
* Using JSON_VALUE here is slightly bogus: perhaps we need to be passed a
* JsonConstructorType so that we can use one of JSON_OBJECTAGG, etc.
*/
if (exprType(expr) == UNKNOWNOID)
expr = coerce_to_specific_type(pstate, expr, TEXTOID, "JSON_VALUE");
rawexpr = expr;
exprtype = exprType(expr);
location = exprLocation(expr);
get_type_category_preferred(exprtype, &typcategory, &typispreferred);
if (ve->format->format_type != JS_FORMAT_DEFAULT)
{
if (ve->format->encoding != JS_ENC_DEFAULT && exprtype != BYTEAOID)
ereport(ERROR,
errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("JSON ENCODING clause is only allowed for bytea input type"),
parser_errposition(pstate, ve->format->location));
if (exprtype == JSONOID || exprtype == JSONBOID)
{
format = JS_FORMAT_DEFAULT; /* do not format json[b] types */
ereport(WARNING,
errmsg("FORMAT JSON has no effect for json and jsonb types"),
parser_errposition(pstate, ve->format->location));
}
else
format = ve->format->format_type;
}
else if (exprtype == JSONOID || exprtype == JSONBOID)
format = JS_FORMAT_DEFAULT; /* do not format json[b] types */
else
format = default_format;
if (format != JS_FORMAT_DEFAULT)
{
Oid targettype = format == JS_FORMAT_JSONB ? JSONBOID : JSONOID;
Node *orig = makeCaseTestExpr(expr);
Node *coerced;
expr = orig;
if (exprtype != BYTEAOID && typcategory != TYPCATEGORY_STRING)
ereport(ERROR,
errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg(ve->format->format_type == JS_FORMAT_DEFAULT ?
"cannot use non-string types with implicit FORMAT JSON clause" :
"cannot use non-string types with explicit FORMAT JSON clause"),
parser_errposition(pstate, ve->format->location >= 0 ?
ve->format->location : location));
/* Convert encoded JSON text from bytea. */
if (format == JS_FORMAT_JSON && exprtype == BYTEAOID)
{
expr = makeJsonByteaToTextConversion(expr, ve->format, location);
exprtype = TEXTOID;
}
/* Try to coerce to the target type. */
coerced = coerce_to_target_type(pstate, expr, exprtype,
targettype, -1,
COERCION_EXPLICIT,
COERCE_EXPLICIT_CAST,
location);
if (!coerced)
{
/* If coercion failed, use to_json()/to_jsonb() functions. */
Oid fnoid = targettype == JSONOID ? F_TO_JSON : F_TO_JSONB;
FuncExpr *fexpr = makeFuncExpr(fnoid, targettype,
list_make1(expr),
InvalidOid, InvalidOid,
COERCE_EXPLICIT_CALL);
fexpr->location = location;
coerced = (Node *) fexpr;
}
if (coerced == orig)
expr = rawexpr;
else
{
ve = copyObject(ve);
ve->raw_expr = (Expr *) rawexpr;
ve->formatted_expr = (Expr *) coerced;
expr = (Node *) ve;
}
}
return expr;
}
/*
* Checks specified output format for its applicability to the target type.
*/
static void
checkJsonOutputFormat(ParseState *pstate, const JsonFormat *format,
Oid targettype, bool allow_format_for_non_strings)
{
if (!allow_format_for_non_strings &&
format->format_type != JS_FORMAT_DEFAULT &&
(targettype != BYTEAOID &&
targettype != JSONOID &&
targettype != JSONBOID))
{
char typcategory;
bool typispreferred;
get_type_category_preferred(targettype, &typcategory, &typispreferred);
if (typcategory != TYPCATEGORY_STRING)
ereport(ERROR,
errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
parser_errposition(pstate, format->location),
errmsg("cannot use JSON format with non-string output types"));
}
if (format->format_type == JS_FORMAT_JSON)
{
JsonEncoding enc = format->encoding != JS_ENC_DEFAULT ?
format->encoding : JS_ENC_UTF8;
if (targettype != BYTEAOID &&
format->encoding != JS_ENC_DEFAULT)
ereport(ERROR,
errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
parser_errposition(pstate, format->location),
errmsg("cannot set JSON encoding for non-bytea output types"));
if (enc != JS_ENC_UTF8)
ereport(ERROR,
errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("unsupported JSON encoding"),
errhint("Only UTF8 JSON encoding is supported."),
parser_errposition(pstate, format->location));
}
}
/*
* Transform JSON output clause.
*
* Assigns target type oid and modifier.
* Assigns default format or checks specified format for its applicability to
* the target type.
*/
static JsonReturning *
transformJsonOutput(ParseState *pstate, const JsonOutput *output,
bool allow_format)
{
JsonReturning *ret;
/* if output clause is not specified, make default clause value */
if (!output)
{
ret = makeNode(JsonReturning);
ret->format = makeJsonFormat(JS_FORMAT_DEFAULT, JS_ENC_DEFAULT, -1);
ret->typid = InvalidOid;
ret->typmod = -1;
return ret;
}
ret = copyObject(output->returning);
typenameTypeIdAndMod(pstate, output->typeName, &ret->typid, &ret->typmod);
if (output->typeName->setof)
ereport(ERROR,
errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("returning SETOF types is not supported in SQL/JSON functions"));
if (ret->format->format_type == JS_FORMAT_DEFAULT)
/* assign JSONB format when returning jsonb, or JSON format otherwise */
ret->format->format_type =
ret->typid == JSONBOID ? JS_FORMAT_JSONB : JS_FORMAT_JSON;
else
checkJsonOutputFormat(pstate, ret->format, ret->typid, allow_format);
return ret;
}
/*
* Transform JSON output clause of JSON constructor functions.
*
* Derive RETURNING type, if not specified, from argument types.
*/
static JsonReturning *
transformJsonConstructorOutput(ParseState *pstate, JsonOutput *output,
List *args)
{
JsonReturning *returning = transformJsonOutput(pstate, output, true);
if (!OidIsValid(returning->typid))
{
ListCell *lc;
bool have_jsonb = false;
foreach(lc, args)
{
Node *expr = lfirst(lc);
Oid typid = exprType(expr);
have_jsonb |= typid == JSONBOID;
if (have_jsonb)
break;
}
if (have_jsonb)
{
returning->typid = JSONBOID;
returning->format->format_type = JS_FORMAT_JSONB;
}
else
{
/* XXX TEXT is default by the standard, but we return JSON */
returning->typid = JSONOID;
returning->format->format_type = JS_FORMAT_JSON;
}
returning->typmod = -1;
}
return returning;
}
/*
* Coerce json[b]-valued function expression to the output type.
*/
static Node *
coerceJsonFuncExpr(ParseState *pstate, Node *expr,
const JsonReturning *returning, bool report_error)
{
Node *res;
int location;
Oid exprtype = exprType(expr);
/* if output type is not specified or equals to function type, return */
if (!OidIsValid(returning->typid) || returning->typid == exprtype)
return expr;
location = exprLocation(expr);
if (location < 0)
location = returning->format->location;
/* special case for RETURNING bytea FORMAT json */
if (returning->format->format_type == JS_FORMAT_JSON &&
returning->typid == BYTEAOID)
{
/* encode json text into bytea using pg_convert_to() */
Node *texpr = coerce_to_specific_type(pstate, expr, TEXTOID,
"JSON_FUNCTION");
Const *enc = getJsonEncodingConst(returning->format);
FuncExpr *fexpr = makeFuncExpr(F_CONVERT_TO, BYTEAOID,
list_make2(texpr, enc),
InvalidOid, InvalidOid,
COERCE_EXPLICIT_CALL);
fexpr->location = location;
return (Node *) fexpr;
}
/* try to coerce expression to the output type */
res = coerce_to_target_type(pstate, expr, exprtype,
returning->typid, returning->typmod,
/* XXX throwing errors when casting to char(N) */
COERCION_EXPLICIT,
COERCE_EXPLICIT_CAST,
location);
if (!res && report_error)
ereport(ERROR,
errcode(ERRCODE_CANNOT_COERCE),
errmsg("cannot cast type %s to %s",
format_type_be(exprtype),
format_type_be(returning->typid)),
parser_coercion_errposition(pstate, location, expr));
return res;
}
/*
* Make a JsonConstructorExpr node.
*/
static Node *
makeJsonConstructorExpr(ParseState *pstate, JsonConstructorType type,
List *args, Expr *fexpr, JsonReturning *returning,
bool unique, bool absent_on_null, int location)
{
JsonConstructorExpr *jsctor = makeNode(JsonConstructorExpr);
Node *placeholder;
Node *coercion;
jsctor->args = args;
jsctor->func = fexpr;
jsctor->type = type;
jsctor->returning = returning;
jsctor->unique = unique;
jsctor->absent_on_null = absent_on_null;
jsctor->location = location;
if (fexpr)
placeholder = makeCaseTestExpr((Node *) fexpr);
else
{
CaseTestExpr *cte = makeNode(CaseTestExpr);
cte->typeId = returning->format->format_type == JS_FORMAT_JSONB ?
JSONBOID : JSONOID;
cte->typeMod = -1;
cte->collation = InvalidOid;
placeholder = (Node *) cte;
}
coercion = coerceJsonFuncExpr(pstate, placeholder, returning, true);
if (coercion != placeholder)
jsctor->coercion = (Expr *) coercion;
return (Node *) jsctor;
}
/*
* Transform JSON_OBJECT() constructor.
*
* JSON_OBJECT() is transformed into json[b]_build_object[_ext]() call
* depending on the output JSON format. The first two arguments of
* json[b]_build_object_ext() are absent_on_null and check_unique.
*
* Then function call result is coerced to the target type.
*/
static Node *
transformJsonObjectConstructor(ParseState *pstate, JsonObjectConstructor *ctor)
{
JsonReturning *returning;
List *args = NIL;
/* transform key-value pairs, if any */
if (ctor->exprs)
{
ListCell *lc;
/* transform and append key-value arguments */
foreach(lc, ctor->exprs)
{
JsonKeyValue *kv = castNode(JsonKeyValue, lfirst(lc));
Node *key = transformExprRecurse(pstate, (Node *) kv->key);
Node *val = transformJsonValueExpr(pstate, kv->value,
JS_FORMAT_DEFAULT);
args = lappend(args, key);
args = lappend(args, val);
}
}
returning = transformJsonConstructorOutput(pstate, ctor->output, args);
return makeJsonConstructorExpr(pstate, JSCTOR_JSON_OBJECT, args, NULL,
returning, ctor->unique,
ctor->absent_on_null, ctor->location);
}
/*
* Transform JSON_ARRAY(query [FORMAT] [RETURNING] [ON NULL]) into
* (SELECT JSON_ARRAYAGG(a [FORMAT] [RETURNING] [ON NULL]) FROM (query) q(a))
*/
static Node *
transformJsonArrayQueryConstructor(ParseState *pstate,
JsonArrayQueryConstructor *ctor)
{
SubLink *sublink = makeNode(SubLink);
SelectStmt *select = makeNode(SelectStmt);
RangeSubselect *range = makeNode(RangeSubselect);
Alias *alias = makeNode(Alias);
ResTarget *target = makeNode(ResTarget);
JsonArrayAgg *agg = makeNode(JsonArrayAgg);
ColumnRef *colref = makeNode(ColumnRef);
Query *query;
ParseState *qpstate;
/* Transform query only for counting target list entries. */
qpstate = make_parsestate(pstate);
query = transformStmt(qpstate, ctor->query);
if (count_nonjunk_tlist_entries(query->targetList) != 1)
ereport(ERROR,
errcode(ERRCODE_SYNTAX_ERROR),
errmsg("subquery must return only one column"),
parser_errposition(pstate, ctor->location));
free_parsestate(qpstate);
colref->fields = list_make2(makeString(pstrdup("q")),
makeString(pstrdup("a")));
colref->location = ctor->location;
agg->arg = makeJsonValueExpr((Expr *) colref, ctor->format);
agg->absent_on_null = ctor->absent_on_null;
agg->constructor = makeNode(JsonAggConstructor);
agg->constructor->agg_order = NIL;
agg->constructor->output = ctor->output;
agg->constructor->location = ctor->location;
target->name = NULL;
target->indirection = NIL;
target->val = (Node *) agg;
target->location = ctor->location;
alias->aliasname = pstrdup("q");
alias->colnames = list_make1(makeString(pstrdup("a")));
range->lateral = false;
range->subquery = ctor->query;
range->alias = alias;
select->targetList = list_make1(target);
select->fromClause = list_make1(range);
sublink->subLinkType = EXPR_SUBLINK;
sublink->subLinkId = 0;
sublink->testexpr = NULL;
sublink->operName = NIL;
sublink->subselect = (Node *) select;
sublink->location = ctor->location;
return transformExprRecurse(pstate, (Node *) sublink);
}
/*
* Common code for JSON_OBJECTAGG and JSON_ARRAYAGG transformation.
*/
static Node *
transformJsonAggConstructor(ParseState *pstate, JsonAggConstructor *agg_ctor,
JsonReturning *returning, List *args,
Oid aggfnoid, Oid aggtype,
JsonConstructorType ctor_type,
bool unique, bool absent_on_null)
{
Node *node;
Expr *aggfilter;
aggfilter = agg_ctor->agg_filter ? (Expr *)
transformWhereClause(pstate, agg_ctor->agg_filter,
EXPR_KIND_FILTER, "FILTER") : NULL;
if (agg_ctor->over)
{
/* window function */
WindowFunc *wfunc = makeNode(WindowFunc);
wfunc->winfnoid = aggfnoid;
wfunc->wintype = aggtype;
/* wincollid and inputcollid will be set by parse_collate.c */
wfunc->args = args;
wfunc->aggfilter = aggfilter;
/* winref will be set by transformWindowFuncCall */
wfunc->winstar = false;
wfunc->winagg = true;
wfunc->location = agg_ctor->location;
/*
* ordered aggs not allowed in windows yet
*/
if (agg_ctor->agg_order != NIL)
ereport(ERROR,
errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("aggregate ORDER BY is not implemented for window functions"),
parser_errposition(pstate, agg_ctor->location));
/* parse_agg.c does additional window-func-specific processing */
transformWindowFuncCall(pstate, wfunc, agg_ctor->over);
node = (Node *) wfunc;
}
else
{
Aggref *aggref = makeNode(Aggref);
aggref->aggfnoid = aggfnoid;
aggref->aggtype = aggtype;
/* aggcollid and inputcollid will be set by parse_collate.c */
/* aggtranstype will be set by planner */
/* aggargtypes will be set by transformAggregateCall */
/* aggdirectargs and args will be set by transformAggregateCall */
/* aggorder and aggdistinct will be set by transformAggregateCall */
aggref->aggfilter = aggfilter;
aggref->aggstar = false;
aggref->aggvariadic = false;
aggref->aggkind = AGGKIND_NORMAL;
aggref->aggpresorted = false;
/* agglevelsup will be set by transformAggregateCall */
aggref->aggsplit = AGGSPLIT_SIMPLE; /* planner might change this */
aggref->aggno = -1; /* planner will set aggno and aggtransno */
aggref->aggtransno = -1;
aggref->location = agg_ctor->location;
transformAggregateCall(pstate, aggref, args, agg_ctor->agg_order, false);
node = (Node *) aggref;
}
return makeJsonConstructorExpr(pstate, ctor_type, NIL, (Expr *) node,
returning, unique, absent_on_null,
agg_ctor->location);
}
/*
* Transform JSON_OBJECTAGG() aggregate function.
*
* JSON_OBJECTAGG() is transformed into
* json[b]_objectagg[_unique][_strict](key, value) call depending on
* the output JSON format. Then the function call result is coerced to the
* target output type.
*/
static Node *
transformJsonObjectAgg(ParseState *pstate, JsonObjectAgg *agg)
{
JsonReturning *returning;
Node *key;
Node *val;
List *args;
Oid aggfnoid;
Oid aggtype;
key = transformExprRecurse(pstate, (Node *) agg->arg->key);
val = transformJsonValueExpr(pstate, agg->arg->value, JS_FORMAT_DEFAULT);
args = list_make2(key, val);
returning = transformJsonConstructorOutput(pstate, agg->constructor->output,
args);
if (returning->format->format_type == JS_FORMAT_JSONB)
{
if (agg->absent_on_null)
if (agg->unique)
aggfnoid = F_JSONB_OBJECT_AGG_UNIQUE_STRICT;
else
aggfnoid = F_JSONB_OBJECT_AGG_STRICT;
else if (agg->unique)
aggfnoid = F_JSONB_OBJECT_AGG_UNIQUE;
else
aggfnoid = F_JSONB_OBJECT_AGG;
aggtype = JSONBOID;
}
else
{
if (agg->absent_on_null)
if (agg->unique)
aggfnoid = F_JSON_OBJECT_AGG_UNIQUE_STRICT;
else
aggfnoid = F_JSON_OBJECT_AGG_STRICT;
else if (agg->unique)
aggfnoid = F_JSON_OBJECT_AGG_UNIQUE;
else
aggfnoid = F_JSON_OBJECT_AGG;
aggtype = JSONOID;
}
return transformJsonAggConstructor(pstate, agg->constructor, returning,
args, aggfnoid, aggtype,
JSCTOR_JSON_OBJECTAGG,
agg->unique, agg->absent_on_null);
}
/*
* Transform JSON_ARRAYAGG() aggregate function.
*
* JSON_ARRAYAGG() is transformed into json[b]_agg[_strict]() call depending
* on the output JSON format and absent_on_null. Then the function call result
* is coerced to the target output type.
*/
static Node *
transformJsonArrayAgg(ParseState *pstate, JsonArrayAgg *agg)
{
JsonReturning *returning;
Node *arg;
Oid aggfnoid;
Oid aggtype;
arg = transformJsonValueExpr(pstate, agg->arg, JS_FORMAT_DEFAULT);
returning = transformJsonConstructorOutput(pstate, agg->constructor->output,
list_make1(arg));
if (returning->format->format_type == JS_FORMAT_JSONB)
{
aggfnoid = agg->absent_on_null ? F_JSONB_AGG_STRICT : F_JSONB_AGG;
aggtype = JSONBOID;
}
else
{
aggfnoid = agg->absent_on_null ? F_JSON_AGG_STRICT : F_JSON_AGG;
aggtype = JSONOID;
}
return transformJsonAggConstructor(pstate, agg->constructor, returning,
list_make1(arg), aggfnoid, aggtype,
JSCTOR_JSON_ARRAYAGG,
false, agg->absent_on_null);
}
/*
* Transform JSON_ARRAY() constructor.
*
* JSON_ARRAY() is transformed into json[b]_build_array[_ext]() call
* depending on the output JSON format. The first argument of
* json[b]_build_array_ext() is absent_on_null.
*
* Then function call result is coerced to the target type.
*/
static Node *
transformJsonArrayConstructor(ParseState *pstate, JsonArrayConstructor *ctor)
{
JsonReturning *returning;
List *args = NIL;
/* transform element expressions, if any */
if (ctor->exprs)
{
ListCell *lc;
/* transform and append element arguments */
foreach(lc, ctor->exprs)
{
JsonValueExpr *jsval = castNode(JsonValueExpr, lfirst(lc));
Node *val = transformJsonValueExpr(pstate, jsval,
JS_FORMAT_DEFAULT);
args = lappend(args, val);
}
}
returning = transformJsonConstructorOutput(pstate, ctor->output, args);
return makeJsonConstructorExpr(pstate, JSCTOR_JSON_ARRAY, args, NULL,
returning, false, ctor->absent_on_null,
ctor->location);
}
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