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9f65aaa408
postgresql/src/backend/parser/parse_target.c
Michael Paquier 9f65aaa408 Remove unused argument "isSlice" from transformAssignmentSubscripts() 
Since c7aba7c, the transform method used during parse analysis of a
subcripting construct has moved from transformAssignmentSubscripts() to
the per-type transform method (arrays or arbitrary types) the step that
checks for slicing support, but transformAssignmentSubscripts() has kept
traces of it.  Removing it simplifies the code, so let's clean up all
that.

Author: Zhang Mingli
Reviewed-by: Richard Guo
Discussion: https://postgr.es/m/0d7041ac-c704-48ad-86fd-e05feddf08ed@Spark
2022-09-18 15:33:16 +09:00

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/*-------------------------------------------------------------------------
*
* parse_target.c
* handle target lists
*
* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/parser/parse_target.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "catalog/pg_type.h"
#include "commands/dbcommands.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "parser/parse_coerce.h"
#include "parser/parse_expr.h"
#include "parser/parse_func.h"
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
#include "parser/parsetree.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/typcache.h"
static void markTargetListOrigin(ParseState *pstate, TargetEntry *tle,
Var *var, int levelsup);
static Node *transformAssignmentSubscripts(ParseState *pstate,
Node *basenode,
const char *targetName,
Oid targetTypeId,
int32 targetTypMod,
Oid targetCollation,
List *subscripts,
List *indirection,
ListCell *next_indirection,
Node *rhs,
CoercionContext ccontext,
int location);
static List *ExpandColumnRefStar(ParseState *pstate, ColumnRef *cref,
bool make_target_entry);
static List *ExpandAllTables(ParseState *pstate, int location);
static List *ExpandIndirectionStar(ParseState *pstate, A_Indirection *ind,
bool make_target_entry, ParseExprKind exprKind);
static List *ExpandSingleTable(ParseState *pstate, ParseNamespaceItem *nsitem,
int sublevels_up, int location,
bool make_target_entry);
static List *ExpandRowReference(ParseState *pstate, Node *expr,
bool make_target_entry);
static int FigureColnameInternal(Node *node, char **name);
/*
* transformTargetEntry()
* Transform any ordinary "expression-type" node into a targetlist entry.
* This is exported so that parse_clause.c can generate targetlist entries
* for ORDER/GROUP BY items that are not already in the targetlist.
*
* node the (untransformed) parse tree for the value expression.
* expr the transformed expression, or NULL if caller didn't do it yet.
* exprKind expression kind (EXPR_KIND_SELECT_TARGET, etc)
* colname the column name to be assigned, or NULL if none yet set.
* resjunk true if the target should be marked resjunk, ie, it is not
* wanted in the final projected tuple.
*/
TargetEntry *
transformTargetEntry(ParseState *pstate,
Node *node,
Node *expr,
ParseExprKind exprKind,
char *colname,
bool resjunk)
{
/* Transform the node if caller didn't do it already */
if (expr == NULL)
{
/*
* If it's a SetToDefault node and we should allow that, pass it
* through unmodified. (transformExpr will throw the appropriate
* error if we're disallowing it.)
*/
if (exprKind == EXPR_KIND_UPDATE_SOURCE && IsA(node, SetToDefault))
expr = node;
else
expr = transformExpr(pstate, node, exprKind);
}
if (colname == NULL && !resjunk)
{
/*
* Generate a suitable column name for a column without any explicit
* 'AS ColumnName' clause.
*/
colname = FigureColname(node);
}
return makeTargetEntry((Expr *) expr,
(AttrNumber) pstate->p_next_resno++,
colname,
resjunk);
}
/*
* transformTargetList()
* Turns a list of ResTarget's into a list of TargetEntry's.
*
* This code acts mostly the same for SELECT, UPDATE, or RETURNING lists;
* the main thing is to transform the given expressions (the "val" fields).
* The exprKind parameter distinguishes these cases when necessary.
*/
List *
transformTargetList(ParseState *pstate, List *targetlist,
ParseExprKind exprKind)
{
List *p_target = NIL;
bool expand_star;
ListCell *o_target;
/* Shouldn't have any leftover multiassign items at start */
Assert(pstate->p_multiassign_exprs == NIL);
/* Expand "something.*" in SELECT and RETURNING, but not UPDATE */
expand_star = (exprKind != EXPR_KIND_UPDATE_SOURCE);
foreach(o_target, targetlist)
{
ResTarget *res = (ResTarget *) lfirst(o_target);
/*
* Check for "something.*". Depending on the complexity of the
* "something", the star could appear as the last field in ColumnRef,
* or as the last indirection item in A_Indirection.
*/
if (expand_star)
{
if (IsA(res->val, ColumnRef))
{
ColumnRef *cref = (ColumnRef *) res->val;
if (IsA(llast(cref->fields), A_Star))
{
/* It is something.*, expand into multiple items */
p_target = list_concat(p_target,
ExpandColumnRefStar(pstate,
cref,
true));
continue;
}
}
else if (IsA(res->val, A_Indirection))
{
A_Indirection *ind = (A_Indirection *) res->val;
if (IsA(llast(ind->indirection), A_Star))
{
/* It is something.*, expand into multiple items */
p_target = list_concat(p_target,
ExpandIndirectionStar(pstate,
ind,
true,
exprKind));
continue;
}
}
}
/*
* Not "something.*", or we want to treat that as a plain whole-row
* variable, so transform as a single expression
*/
p_target = lappend(p_target,
transformTargetEntry(pstate,
res->val,
NULL,
exprKind,
res->name,
false));
}
/*
* If any multiassign resjunk items were created, attach them to the end
* of the targetlist. This should only happen in an UPDATE tlist. We
* don't need to worry about numbering of these items; transformUpdateStmt
* will set their resnos.
*/
if (pstate->p_multiassign_exprs)
{
Assert(exprKind == EXPR_KIND_UPDATE_SOURCE);
p_target = list_concat(p_target, pstate->p_multiassign_exprs);
pstate->p_multiassign_exprs = NIL;
}
return p_target;
}
/*
* transformExpressionList()
*
* This is the identical transformation to transformTargetList, except that
* the input list elements are bare expressions without ResTarget decoration,
* and the output elements are likewise just expressions without TargetEntry
* decoration. Also, we don't expect any multiassign constructs within the
* list, so there's nothing to do for that. We use this for ROW() and
* VALUES() constructs.
*
* exprKind is not enough to tell us whether to allow SetToDefault, so
* an additional flag is needed for that.
*/
List *
transformExpressionList(ParseState *pstate, List *exprlist,
ParseExprKind exprKind, bool allowDefault)
{
List *result = NIL;
ListCell *lc;
foreach(lc, exprlist)
{
Node *e = (Node *) lfirst(lc);
/*
* Check for "something.*". Depending on the complexity of the
* "something", the star could appear as the last field in ColumnRef,
* or as the last indirection item in A_Indirection.
*/
if (IsA(e, ColumnRef))
{
ColumnRef *cref = (ColumnRef *) e;
if (IsA(llast(cref->fields), A_Star))
{
/* It is something.*, expand into multiple items */
result = list_concat(result,
ExpandColumnRefStar(pstate, cref,
false));
continue;
}
}
else if (IsA(e, A_Indirection))
{
A_Indirection *ind = (A_Indirection *) e;
if (IsA(llast(ind->indirection), A_Star))
{
/* It is something.*, expand into multiple items */
result = list_concat(result,
ExpandIndirectionStar(pstate, ind,
false, exprKind));
continue;
}
}
/*
* Not "something.*", so transform as a single expression. If it's a
* SetToDefault node and we should allow that, pass it through
* unmodified. (transformExpr will throw the appropriate error if
* we're disallowing it.)
*/
if (allowDefault && IsA(e, SetToDefault))
/* do nothing */ ;
else
e = transformExpr(pstate, e, exprKind);
result = lappend(result, e);
}
return result;
}
/*
* resolveTargetListUnknowns()
* Convert any unknown-type targetlist entries to type TEXT.
*
* We do this after we've exhausted all other ways of identifying the output
* column types of a query.
*/
void
resolveTargetListUnknowns(ParseState *pstate, List *targetlist)
{
ListCell *l;
foreach(l, targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Oid restype = exprType((Node *) tle->expr);
if (restype == UNKNOWNOID)
{
tle->expr = (Expr *) coerce_type(pstate, (Node *) tle->expr,
restype, TEXTOID, -1,
COERCION_IMPLICIT,
COERCE_IMPLICIT_CAST,
-1);
}
}
}
/*
* markTargetListOrigins()
* Mark targetlist columns that are simple Vars with the source
* table's OID and column number.
*
* Currently, this is done only for SELECT targetlists and RETURNING lists,
* since we only need the info if we are going to send it to the frontend.
*/
void
markTargetListOrigins(ParseState *pstate, List *targetlist)
{
ListCell *l;
foreach(l, targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
markTargetListOrigin(pstate, tle, (Var *) tle->expr, 0);
}
}
/*
* markTargetListOrigin()
* If 'var' is a Var of a plain relation, mark 'tle' with its origin
*
* levelsup is an extra offset to interpret the Var's varlevelsup correctly.
*
* Note that we do not drill down into views, but report the view as the
* column owner. There's also no need to drill down into joins: if we see
* a join alias Var, it must be a merged JOIN USING column (or possibly a
* whole-row Var); that is not a direct reference to any plain table column,
* so we don't report it.
*/
static void
markTargetListOrigin(ParseState *pstate, TargetEntry *tle,
Var *var, int levelsup)
{
int netlevelsup;
RangeTblEntry *rte;
AttrNumber attnum;
if (var == NULL || !IsA(var, Var))
return;
netlevelsup = var->varlevelsup + levelsup;
rte = GetRTEByRangeTablePosn(pstate, var->varno, netlevelsup);
attnum = var->varattno;
switch (rte->rtekind)
{
case RTE_RELATION:
/* It's a table or view, report it */
tle->resorigtbl = rte->relid;
tle->resorigcol = attnum;
break;
case RTE_SUBQUERY:
/* Subselect-in-FROM: copy up from the subselect */
if (attnum != InvalidAttrNumber)
{
TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
attnum);
if (ste == NULL || ste->resjunk)
elog(ERROR, "subquery %s does not have attribute %d",
rte->eref->aliasname, attnum);
tle->resorigtbl = ste->resorigtbl;
tle->resorigcol = ste->resorigcol;
}
break;
case RTE_JOIN:
case RTE_FUNCTION:
case RTE_VALUES:
case RTE_TABLEFUNC:
case RTE_NAMEDTUPLESTORE:
case RTE_RESULT:
/* not a simple relation, leave it unmarked */
break;
case RTE_CTE:
/*
* CTE reference: copy up from the subquery, if possible. If the
* RTE is a recursive self-reference then we can't do anything
* because we haven't finished analyzing it yet. However, it's no
* big loss because we must be down inside the recursive term of a
* recursive CTE, and so any markings on the current targetlist
* are not going to affect the results anyway.
*/
if (attnum != InvalidAttrNumber && !rte->self_reference)
{
CommonTableExpr *cte = GetCTEForRTE(pstate, rte, netlevelsup);
TargetEntry *ste;
List *tl = GetCTETargetList(cte);
int extra_cols = 0;
/*
* RTE for CTE will already have the search and cycle columns
* added, but the subquery won't, so skip looking those up.
*/
if (cte->search_clause)
extra_cols += 1;
if (cte->cycle_clause)
extra_cols += 2;
if (extra_cols &&
attnum > list_length(tl) &&
attnum <= list_length(tl) + extra_cols)
break;
ste = get_tle_by_resno(tl, attnum);
if (ste == NULL || ste->resjunk)
elog(ERROR, "CTE %s does not have attribute %d",
rte->eref->aliasname, attnum);
tle->resorigtbl = ste->resorigtbl;
tle->resorigcol = ste->resorigcol;
}
break;
}
}
/*
* transformAssignedExpr()
* This is used in INSERT and UPDATE statements only. It prepares an
* expression for assignment to a column of the target table.
* This includes coercing the given value to the target column's type
* (if necessary), and dealing with any subfield names or subscripts
* attached to the target column itself. The input expression has
* already been through transformExpr().
*
* pstate parse state
* expr expression to be modified
* exprKind indicates which type of statement we're dealing with
* colname target column name (ie, name of attribute to be assigned to)
* attrno target attribute number
* indirection subscripts/field names for target column, if any
* location error cursor position for the target column, or -1
*
* Returns the modified expression.
*
* Note: location points at the target column name (SET target or INSERT
* column name list entry), and must therefore be -1 in an INSERT that
* omits the column name list. So we should usually prefer to use
* exprLocation(expr) for errors that can happen in a default INSERT.
*/
Expr *
transformAssignedExpr(ParseState *pstate,
Expr *expr,
ParseExprKind exprKind,
const char *colname,
int attrno,
List *indirection,
int location)
{
Relation rd = pstate->p_target_relation;
Oid type_id; /* type of value provided */
Oid attrtype; /* type of target column */
int32 attrtypmod;
Oid attrcollation; /* collation of target column */
ParseExprKind sv_expr_kind;
/*
* Save and restore identity of expression type we're parsing. We must
* set p_expr_kind here because we can parse subscripts without going
* through transformExpr().
*/
Assert(exprKind != EXPR_KIND_NONE);
sv_expr_kind = pstate->p_expr_kind;
pstate->p_expr_kind = exprKind;
Assert(rd != NULL);
if (attrno <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot assign to system column \"%s\"",
colname),
parser_errposition(pstate, location)));
attrtype = attnumTypeId(rd, attrno);
attrtypmod = TupleDescAttr(rd->rd_att, attrno - 1)->atttypmod;
attrcollation = TupleDescAttr(rd->rd_att, attrno - 1)->attcollation;
/*
* If the expression is a DEFAULT placeholder, insert the attribute's
* type/typmod/collation into it so that exprType etc will report the
* right things. (We expect that the eventually substituted default
* expression will in fact have this type and typmod. The collation
* likely doesn't matter, but let's set it correctly anyway.) Also,
* reject trying to update a subfield or array element with DEFAULT, since
* there can't be any default for portions of a column.
*/
if (expr && IsA(expr, SetToDefault))
{
SetToDefault *def = (SetToDefault *) expr;
def->typeId = attrtype;
def->typeMod = attrtypmod;
def->collation = attrcollation;
if (indirection)
{
if (IsA(linitial(indirection), A_Indices))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot set an array element to DEFAULT"),
parser_errposition(pstate, location)));
else
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot set a subfield to DEFAULT"),
parser_errposition(pstate, location)));
}
}
/* Now we can use exprType() safely. */
type_id = exprType((Node *) expr);
/*
* If there is indirection on the target column, prepare an array or
* subfield assignment expression. This will generate a new column value
* that the source value has been inserted into, which can then be placed
* in the new tuple constructed by INSERT or UPDATE.
*/
if (indirection)
{
Node *colVar;
if (pstate->p_is_insert)
{
/*
* The command is INSERT INTO table (col.something) ... so there
* is not really a source value to work with. Insert a NULL
* constant as the source value.
*/
colVar = (Node *) makeNullConst(attrtype, attrtypmod,
attrcollation);
}
else
{
/*
* Build a Var for the column to be updated.
*/
Var *var;
var = makeVar(pstate->p_target_nsitem->p_rtindex, attrno,
attrtype, attrtypmod, attrcollation, 0);
var->location = location;
colVar = (Node *) var;
}
expr = (Expr *)
transformAssignmentIndirection(pstate,
colVar,
colname,
false,
attrtype,
attrtypmod,
attrcollation,
indirection,
list_head(indirection),
(Node *) expr,
COERCION_ASSIGNMENT,
location);
}
else
{
/*
* For normal non-qualified target column, do type checking and
* coercion.
*/
Node *orig_expr = (Node *) expr;
expr = (Expr *)
coerce_to_target_type(pstate,
orig_expr, type_id,
attrtype, attrtypmod,
COERCION_ASSIGNMENT,
COERCE_IMPLICIT_CAST,
-1);
if (expr == NULL)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column \"%s\" is of type %s"
" but expression is of type %s",
colname,
format_type_be(attrtype),
format_type_be(type_id)),
errhint("You will need to rewrite or cast the expression."),
parser_errposition(pstate, exprLocation(orig_expr))));
}
pstate->p_expr_kind = sv_expr_kind;
return expr;
}
/*
* updateTargetListEntry()
* This is used in UPDATE statements (and ON CONFLICT DO UPDATE)
* only. It prepares an UPDATE TargetEntry for assignment to a
* column of the target table. This includes coercing the given
* value to the target column's type (if necessary), and dealing with
* any subfield names or subscripts attached to the target column
* itself.
*
* pstate parse state
* tle target list entry to be modified
* colname target column name (ie, name of attribute to be assigned to)
* attrno target attribute number
* indirection subscripts/field names for target column, if any
* location error cursor position (should point at column name), or -1
*/
void
updateTargetListEntry(ParseState *pstate,
TargetEntry *tle,
char *colname,
int attrno,
List *indirection,
int location)
{
/* Fix up expression as needed */
tle->expr = transformAssignedExpr(pstate,
tle->expr,
EXPR_KIND_UPDATE_TARGET,
colname,
attrno,
indirection,
location);
/*
* Set the resno to identify the target column --- the rewriter and
* planner depend on this. We also set the resname to identify the target
* column, but this is only for debugging purposes; it should not be
* relied on. (In particular, it might be out of date in a stored rule.)
*/
tle->resno = (AttrNumber) attrno;
tle->resname = colname;
}
/*
* Process indirection (field selection or subscripting) of the target
* column in INSERT/UPDATE/assignment. This routine recurses for multiple
* levels of indirection --- but note that several adjacent A_Indices nodes
* in the indirection list are treated as a single multidimensional subscript
* operation.
*
* In the initial call, basenode is a Var for the target column in UPDATE,
* or a null Const of the target's type in INSERT, or a Param for the target
* variable in PL/pgSQL assignment. In recursive calls, basenode is NULL,
* indicating that a substitute node should be consed up if needed.
*
* targetName is the name of the field or subfield we're assigning to, and
* targetIsSubscripting is true if we're subscripting it. These are just for
* error reporting.
*
* targetTypeId, targetTypMod, targetCollation indicate the datatype and
* collation of the object to be assigned to (initially the target column,
* later some subobject).
*
* indirection is the list of indirection nodes, and indirection_cell is the
* start of the sublist remaining to process. When it's NULL, we're done
* recursing and can just coerce and return the RHS.
*
* rhs is the already-transformed value to be assigned; note it has not been
* coerced to any particular type.
*
* ccontext is the coercion level to use while coercing the rhs. For
* normal statements it'll be COERCION_ASSIGNMENT, but PL/pgSQL uses
* a special value.
*
* location is the cursor error position for any errors. (Note: this points
* to the head of the target clause, eg "foo" in "foo.bar[baz]". Later we
* might want to decorate indirection cells with their own location info,
* in which case the location argument could probably be dropped.)
*/
Node *
transformAssignmentIndirection(ParseState *pstate,
Node *basenode,
const char *targetName,
bool targetIsSubscripting,
Oid targetTypeId,
int32 targetTypMod,
Oid targetCollation,
List *indirection,
ListCell *indirection_cell,
Node *rhs,
CoercionContext ccontext,
int location)
{
Node *result;
List *subscripts = NIL;
ListCell *i;
if (indirection_cell && !basenode)
{
/*
* Set up a substitution. We abuse CaseTestExpr for this. It's safe
* to do so because the only nodes that will be above the CaseTestExpr
* in the finished expression will be FieldStore and SubscriptingRef
* nodes. (There could be other stuff in the tree, but it will be
* within other child fields of those node types.)
*/
CaseTestExpr *ctest = makeNode(CaseTestExpr);
ctest->typeId = targetTypeId;
ctest->typeMod = targetTypMod;
ctest->collation = targetCollation;
basenode = (Node *) ctest;
}
/*
* 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.
*/
for_each_cell(i, indirection, indirection_cell)
{
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
{
FieldStore *fstore;
Oid baseTypeId;
int32 baseTypeMod;
Oid typrelid;
AttrNumber attnum;
Oid fieldTypeId;
int32 fieldTypMod;
Oid fieldCollation;
Assert(IsA(n, String));
/* process subscripts before this field selection */
if (subscripts)
{
/* recurse, and then return because we're done */
return transformAssignmentSubscripts(pstate,
basenode,
targetName,
targetTypeId,
targetTypMod,
targetCollation,
subscripts,
indirection,
i,
rhs,
ccontext,
location);
}
/* No subscripts, so can process field selection here */
/*
* Look up the composite type, accounting for possibility that
* what we are given is a domain over composite.
*/
baseTypeMod = targetTypMod;
baseTypeId = getBaseTypeAndTypmod(targetTypeId, &baseTypeMod);
typrelid = typeidTypeRelid(baseTypeId);
if (!typrelid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
attnum = get_attnum(typrelid, strVal(n));
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
if (attnum < 0)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("cannot assign to system column \"%s\"",
strVal(n)),
parser_errposition(pstate, location)));
get_atttypetypmodcoll(typrelid, attnum,
&fieldTypeId, &fieldTypMod, &fieldCollation);
/* recurse to create appropriate RHS for field assign */
rhs = transformAssignmentIndirection(pstate,
NULL,
strVal(n),
false,
fieldTypeId,
fieldTypMod,
fieldCollation,
indirection,
lnext(indirection, i),
rhs,
ccontext,
location);
/* and build a FieldStore node */
fstore = makeNode(FieldStore);
fstore->arg = (Expr *) basenode;
fstore->newvals = list_make1(rhs);
fstore->fieldnums = list_make1_int(attnum);
fstore->resulttype = baseTypeId;
/* If target is a domain, apply constraints */
if (baseTypeId != targetTypeId)
return coerce_to_domain((Node *) fstore,
baseTypeId, baseTypeMod,
targetTypeId,
COERCION_IMPLICIT,
COERCE_IMPLICIT_CAST,
location,
false);
return (Node *) fstore;
}
}
/* process trailing subscripts, if any */
if (subscripts)
{
/* recurse, and then return because we're done */
return transformAssignmentSubscripts(pstate,
basenode,
targetName,
targetTypeId,
targetTypMod,
targetCollation,
subscripts,
indirection,
NULL,
rhs,
ccontext,
location);
}
/* base case: just coerce RHS to match target type ID */
result = coerce_to_target_type(pstate,
rhs, exprType(rhs),
targetTypeId, targetTypMod,
ccontext,
COERCE_IMPLICIT_CAST,
-1);
if (result == NULL)
{
if (targetIsSubscripting)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("subscripted assignment to \"%s\" requires type %s"
" but expression is of type %s",
targetName,
format_type_be(targetTypeId),
format_type_be(exprType(rhs))),
errhint("You will need to rewrite or cast the expression."),
parser_errposition(pstate, location)));
else
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("subfield \"%s\" is of type %s"
" but expression is of type %s",
targetName,
format_type_be(targetTypeId),
format_type_be(exprType(rhs))),
errhint("You will need to rewrite or cast the expression."),
parser_errposition(pstate, location)));
}
return result;
}
/*
* helper for transformAssignmentIndirection: process container assignment
*/
static Node *
transformAssignmentSubscripts(ParseState *pstate,
Node *basenode,
const char *targetName,
Oid targetTypeId,
int32 targetTypMod,
Oid targetCollation,
List *subscripts,
List *indirection,
ListCell *next_indirection,
Node *rhs,
CoercionContext ccontext,
int location)
{
Node *result;
SubscriptingRef *sbsref;
Oid containerType;
int32 containerTypMod;
Oid typeNeeded;
int32 typmodNeeded;
Oid collationNeeded;
Assert(subscripts != NIL);
/* Identify the actual container type involved */
containerType = targetTypeId;
containerTypMod = targetTypMod;
transformContainerType(&containerType, &containerTypMod);
/* Process subscripts and identify required type for RHS */
sbsref = transformContainerSubscripts(pstate,
basenode,
containerType,
containerTypMod,
subscripts,
true);
typeNeeded = sbsref->refrestype;
typmodNeeded = sbsref->reftypmod;
/*
* Container normally has same collation as its elements, but there's an
* exception: we might be subscripting a domain over a container type. In
* that case use collation of the base type. (This is shaky for arbitrary
* subscripting semantics, but it doesn't matter all that much since we
* only use this to label the collation of a possible CaseTestExpr.)
*/
if (containerType == targetTypeId)
collationNeeded = targetCollation;
else
collationNeeded = get_typcollation(containerType);
/* recurse to create appropriate RHS for container assign */
rhs = transformAssignmentIndirection(pstate,
NULL,
targetName,
true,
typeNeeded,
typmodNeeded,
collationNeeded,
indirection,
next_indirection,
rhs,
ccontext,
location);
/*
* Insert the already-properly-coerced RHS into the SubscriptingRef. Then
* set refrestype and reftypmod back to the container type's values.
*/
sbsref->refassgnexpr = (Expr *) rhs;
sbsref->refrestype = containerType;
sbsref->reftypmod = containerTypMod;
result = (Node *) sbsref;
/* If target was a domain over container, need to coerce up to the domain */
if (containerType != targetTypeId)
{
Oid resulttype = exprType(result);
result = coerce_to_target_type(pstate,
result, resulttype,
targetTypeId, targetTypMod,
ccontext,
COERCE_IMPLICIT_CAST,
-1);
/* can fail if we had int2vector/oidvector, but not for true domains */
if (result == NULL)
ereport(ERROR,
(errcode(ERRCODE_CANNOT_COERCE),
errmsg("cannot cast type %s to %s",
format_type_be(resulttype),
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
}
return result;
}
/*
* checkInsertTargets -
* generate a list of INSERT column targets if not supplied, or
* test supplied column names to make sure they are in target table.
* Also return an integer list of the columns' attribute numbers.
*/
List *
checkInsertTargets(ParseState *pstate, List *cols, List **attrnos)
{
*attrnos = NIL;
if (cols == NIL)
{
/*
* Generate default column list for INSERT.
*/
int numcol = RelationGetNumberOfAttributes(pstate->p_target_relation);
int i;
for (i = 0; i < numcol; i++)
{
ResTarget *col;
Form_pg_attribute attr;
attr = TupleDescAttr(pstate->p_target_relation->rd_att, i);
if (attr->attisdropped)
continue;
col = makeNode(ResTarget);
col->name = pstrdup(NameStr(attr->attname));
col->indirection = NIL;
col->val = NULL;
col->location = -1;
cols = lappend(cols, col);
*attrnos = lappend_int(*attrnos, i + 1);
}
}
else
{
/*
* Do initial validation of user-supplied INSERT column list.
*/
Bitmapset *wholecols = NULL;
Bitmapset *partialcols = NULL;
ListCell *tl;
foreach(tl, cols)
{
ResTarget *col = (ResTarget *) lfirst(tl);
char *name = col->name;
int attrno;
/* Lookup column name, ereport on failure */
attrno = attnameAttNum(pstate->p_target_relation, name, false);
if (attrno == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
name,
RelationGetRelationName(pstate->p_target_relation)),
parser_errposition(pstate, col->location)));
/*
* Check for duplicates, but only of whole columns --- we allow
* INSERT INTO foo (col.subcol1, col.subcol2)
*/
if (col->indirection == NIL)
{
/* whole column; must not have any other assignment */
if (bms_is_member(attrno, wholecols) ||
bms_is_member(attrno, partialcols))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_COLUMN),
errmsg("column \"%s\" specified more than once",
name),
parser_errposition(pstate, col->location)));
wholecols = bms_add_member(wholecols, attrno);
}
else
{
/* partial column; must not have any whole assignment */
if (bms_is_member(attrno, wholecols))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_COLUMN),
errmsg("column \"%s\" specified more than once",
name),
parser_errposition(pstate, col->location)));
partialcols = bms_add_member(partialcols, attrno);
}
*attrnos = lappend_int(*attrnos, attrno);
}
}
return cols;
}
/*
* ExpandColumnRefStar()
* Transforms foo.* into a list of expressions or targetlist entries.
*
* This handles the case where '*' appears as the last or only item in a
* ColumnRef. The code is shared between the case of foo.* at the top level
* in a SELECT target list (where we want TargetEntry nodes in the result)
* and foo.* in a ROW() or VALUES() construct (where we want just bare
* expressions).
*
* The referenced columns are marked as requiring SELECT access.
*/
static List *
ExpandColumnRefStar(ParseState *pstate, ColumnRef *cref,
bool make_target_entry)
{
List *fields = cref->fields;
int numnames = list_length(fields);
if (numnames == 1)
{
/*
* Target item is a bare '*', expand all tables
*
* (e.g., SELECT * FROM emp, dept)
*
* Since the grammar only accepts bare '*' at top level of SELECT, we
* need not handle the make_target_entry==false case here.
*/
Assert(make_target_entry);
return ExpandAllTables(pstate, cref->location);
}
else
{
/*
* Target item is relation.*, expand that table
*
* (e.g., SELECT emp.*, dname FROM emp, dept)
*
* Note: this code is a lot like transformColumnRef; it's tempting to
* call that instead and then replace the resulting whole-row Var with
* a list of Vars. However, that would leave us with the RTE's
* selectedCols bitmap showing the whole row as needing select
* permission, as well as the individual columns. That would be
* incorrect (since columns added later shouldn't need select
* permissions). We could try to remove the whole-row permission bit
* after the fact, but duplicating code is less messy.
*/
char *nspname = NULL;
char *relname = NULL;
ParseNamespaceItem *nsitem = NULL;
int levels_up;
enum
{
CRSERR_NO_RTE,
CRSERR_WRONG_DB,
CRSERR_TOO_MANY
} crserr = CRSERR_NO_RTE;
/*
* Give the PreParseColumnRefHook, if any, first shot. If it returns
* non-null then we should use that expression.
*/
if (pstate->p_pre_columnref_hook != NULL)
{
Node *node;
node = pstate->p_pre_columnref_hook(pstate, cref);
if (node != NULL)
return ExpandRowReference(pstate, node, make_target_entry);
}
switch (numnames)
{
case 2:
relname = strVal(linitial(fields));
nsitem = refnameNamespaceItem(pstate, nspname, relname,
cref->location,
&levels_up);
break;
case 3:
nspname = strVal(linitial(fields));
relname = strVal(lsecond(fields));
nsitem = refnameNamespaceItem(pstate, nspname, relname,
cref->location,
&levels_up);
break;
case 4:
{
char *catname = strVal(linitial(fields));
/*
* We check the catalog name and then ignore it.
*/
if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
{
crserr = CRSERR_WRONG_DB;
break;
}
nspname = strVal(lsecond(fields));
relname = strVal(lthird(fields));
nsitem = refnameNamespaceItem(pstate, nspname, relname,
cref->location,
&levels_up);
break;
}
default:
crserr = CRSERR_TOO_MANY;
break;
}
/*
* Now give the PostParseColumnRefHook, if any, a chance. We cheat a
* bit by passing the RangeTblEntry, not a Var, as the planned
* translation. (A single Var wouldn't be strictly correct anyway.
* This convention allows hooks that really care to know what is
* happening. It might be better to pass the nsitem, but we'd have to
* promote that struct to a full-fledged Node type so that callees
* could identify its type.)
*/
if (pstate->p_post_columnref_hook != NULL)
{
Node *node;
node = pstate->p_post_columnref_hook(pstate, cref,
(Node *) (nsitem ? nsitem->p_rte : NULL));
if (node != NULL)
{
if (nsitem != NULL)
ereport(ERROR,
(errcode(ERRCODE_AMBIGUOUS_COLUMN),
errmsg("column reference \"%s\" is ambiguous",
NameListToString(cref->fields)),
parser_errposition(pstate, cref->location)));
return ExpandRowReference(pstate, node, make_target_entry);
}
}
/*
* Throw error if no translation found.
*/
if (nsitem == NULL)
{
switch (crserr)
{
case CRSERR_NO_RTE:
errorMissingRTE(pstate, makeRangeVar(nspname, relname,
cref->location));
break;
case CRSERR_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 CRSERR_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;
}
}
/*
* OK, expand the nsitem into fields.
*/
return ExpandSingleTable(pstate, nsitem, levels_up, cref->location,
make_target_entry);
}
}
/*
* ExpandAllTables()
* Transforms '*' (in the target list) into a list of targetlist entries.
*
* tlist entries are generated for each relation visible for unqualified
* column name access. We do not consider qualified-name-only entries because
* that would include input tables of aliasless JOINs, NEW/OLD pseudo-entries,
* etc.
*
* The referenced relations/columns are marked as requiring SELECT access.
*/
static List *
ExpandAllTables(ParseState *pstate, int location)
{
List *target = NIL;
bool found_table = false;
ListCell *l;
foreach(l, pstate->p_namespace)
{
ParseNamespaceItem *nsitem = (ParseNamespaceItem *) lfirst(l);
/* Ignore table-only items */
if (!nsitem->p_cols_visible)
continue;
/* Should not have any lateral-only items when parsing targetlist */
Assert(!nsitem->p_lateral_only);
/* Remember we found a p_cols_visible item */
found_table = true;
target = list_concat(target,
expandNSItemAttrs(pstate,
nsitem,
0,
true,
location));
}
/*
* Check for "SELECT *;". We do it this way, rather than checking for
* target == NIL, because we want to allow SELECT * FROM a zero_column
* table.
*/
if (!found_table)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("SELECT * with no tables specified is not valid"),
parser_errposition(pstate, location)));
return target;
}
/*
* ExpandIndirectionStar()
* Transforms foo.* into a list of expressions or targetlist entries.
*
* This handles the case where '*' appears as the last item in A_Indirection.
* The code is shared between the case of foo.* at the top level in a SELECT
* target list (where we want TargetEntry nodes in the result) and foo.* in
* a ROW() or VALUES() construct (where we want just bare expressions).
* For robustness, we use a separate "make_target_entry" flag to control
* this rather than relying on exprKind.
*/
static List *
ExpandIndirectionStar(ParseState *pstate, A_Indirection *ind,
bool make_target_entry, ParseExprKind exprKind)
{
Node *expr;
/* Strip off the '*' to create a reference to the rowtype object */
ind = copyObject(ind);
ind->indirection = list_truncate(ind->indirection,
list_length(ind->indirection) - 1);
/* And transform that */
expr = transformExpr(pstate, (Node *) ind, exprKind);
/* Expand the rowtype expression into individual fields */
return ExpandRowReference(pstate, expr, make_target_entry);
}
/*
* ExpandSingleTable()
* Transforms foo.* into a list of expressions or targetlist entries.
*
* This handles the case where foo has been determined to be a simple
* reference to an RTE, so we can just generate Vars for the expressions.
*
* The referenced columns are marked as requiring SELECT access.
*/
static List *
ExpandSingleTable(ParseState *pstate, ParseNamespaceItem *nsitem,
int sublevels_up, int location, bool make_target_entry)
{
if (make_target_entry)
{
/* expandNSItemAttrs handles permissions marking */
return expandNSItemAttrs(pstate, nsitem, sublevels_up, true, location);
}
else
{
RangeTblEntry *rte = nsitem->p_rte;
List *vars;
ListCell *l;
vars = expandNSItemVars(nsitem, sublevels_up, location, NULL);
/*
* Require read access to the table. This is normally redundant with
* the markVarForSelectPriv calls below, but not if the table has zero
* columns. We need not do anything if the nsitem is for a join: its
* component tables will have been marked ACL_SELECT when they were
* added to the rangetable. (This step changes things only for the
* target relation of UPDATE/DELETE, which cannot be under a join.)
*/
if (rte->rtekind == RTE_RELATION)
rte->requiredPerms |= ACL_SELECT;
/* Require read access to each column */
foreach(l, vars)
{
Var *var = (Var *) lfirst(l);
markVarForSelectPriv(pstate, var);
}
return vars;
}
}
/*
* ExpandRowReference()
* Transforms foo.* into a list of expressions or targetlist entries.
*
* This handles the case where foo is an arbitrary expression of composite
* type.
*/
static List *
ExpandRowReference(ParseState *pstate, Node *expr,
bool make_target_entry)
{
List *result = NIL;
TupleDesc tupleDesc;
int numAttrs;
int i;
/*
* If the rowtype expression is a whole-row Var, we can expand the fields
* as simple Vars. Note: if the RTE is a relation, this case leaves us
* with the RTE's selectedCols bitmap showing the whole row as needing
* select permission, as well as the individual columns. However, we can
* only get here for weird notations like (table.*).*, so it's not worth
* trying to clean up --- arguably, the permissions marking is correct
* anyway for such cases.
*/
if (IsA(expr, Var) &&
((Var *) expr)->varattno == InvalidAttrNumber)
{
Var *var = (Var *) expr;
ParseNamespaceItem *nsitem;
nsitem = GetNSItemByRangeTablePosn(pstate, var->varno, var->varlevelsup);
return ExpandSingleTable(pstate, nsitem, var->varlevelsup, var->location, make_target_entry);
}
/*
* Otherwise we have to do it the hard way. Our current implementation is
* to generate multiple copies of the expression and do FieldSelects.
* (This can be pretty inefficient if the expression involves nontrivial
* computation :-(.)
*
* Verify it's a composite type, and get the tupdesc.
* get_expr_result_tupdesc() handles this conveniently.
*
* If it's a Var of type RECORD, we have to work even harder: we have to
* find what the Var refers to, and pass that to get_expr_result_tupdesc.
* That task is handled by expandRecordVariable().
*/
if (IsA(expr, Var) &&
((Var *) expr)->vartype == RECORDOID)
tupleDesc = expandRecordVariable(pstate, (Var *) expr, 0);
else
tupleDesc = get_expr_result_tupdesc(expr, false);
Assert(tupleDesc);
/* Generate a list of references to the individual fields */
numAttrs = tupleDesc->natts;
for (i = 0; i < numAttrs; i++)
{
Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
FieldSelect *fselect;
if (att->attisdropped)
continue;
fselect = makeNode(FieldSelect);
fselect->arg = (Expr *) copyObject(expr);
fselect->fieldnum = i + 1;
fselect->resulttype = att->atttypid;
fselect->resulttypmod = att->atttypmod;
/* save attribute's collation for parse_collate.c */
fselect->resultcollid = att->attcollation;
if (make_target_entry)
{
/* add TargetEntry decoration */
TargetEntry *te;
te = makeTargetEntry((Expr *) fselect,
(AttrNumber) pstate->p_next_resno++,
pstrdup(NameStr(att->attname)),
false);
result = lappend(result, te);
}
else
result = lappend(result, fselect);
}
return result;
}
/*
* expandRecordVariable
* Get the tuple descriptor for a Var of type RECORD, if possible.
*
* Since no actual table or view column is allowed to have type RECORD, such
* a Var must refer to a JOIN or FUNCTION RTE or to a subquery output. We
* drill down to find the ultimate defining expression and attempt to infer
* the tupdesc from it. We ereport if we can't determine the tupdesc.
*
* levelsup is an extra offset to interpret the Var's varlevelsup correctly.
*/
TupleDesc
expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
{
TupleDesc tupleDesc;
int netlevelsup;
RangeTblEntry *rte;
AttrNumber attnum;
Node *expr;
/* Check my caller didn't mess up */
Assert(IsA(var, Var));
Assert(var->vartype == RECORDOID);
/*
* Note: it's tempting to use GetNSItemByRangeTablePosn here so that we
* can use expandNSItemVars instead of expandRTE; but that does not work
* for some of the recursion cases below, where we have consed up a
* ParseState that lacks p_namespace data.
*/
netlevelsup = var->varlevelsup + levelsup;
rte = GetRTEByRangeTablePosn(pstate, var->varno, netlevelsup);
attnum = var->varattno;
if (attnum == InvalidAttrNumber)
{
/* Whole-row reference to an RTE, so expand the known fields */
List *names,
*vars;
ListCell *lname,
*lvar;
int i;
expandRTE(rte, var->varno, 0, var->location, false,
&names, &vars);
tupleDesc = CreateTemplateTupleDesc(list_length(vars));
i = 1;
forboth(lname, names, lvar, vars)
{
char *label = strVal(lfirst(lname));
Node *varnode = (Node *) lfirst(lvar);
TupleDescInitEntry(tupleDesc, i,
label,
exprType(varnode),
exprTypmod(varnode),
0);
TupleDescInitEntryCollation(tupleDesc, i,
exprCollation(varnode));
i++;
}
Assert(lname == NULL && lvar == NULL); /* lists same length? */
return tupleDesc;
}
expr = (Node *) var; /* default if we can't drill down */
switch (rte->rtekind)
{
case RTE_RELATION:
case RTE_VALUES:
case RTE_NAMEDTUPLESTORE:
case RTE_RESULT:
/*
* This case should not occur: a column of a table, values list,
* or ENR shouldn't have type RECORD. Fall through and fail (most
* likely) at the bottom.
*/
break;
case RTE_SUBQUERY:
{
/* Subselect-in-FROM: examine sub-select's output expr */
TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
attnum);
if (ste == NULL || ste->resjunk)
elog(ERROR, "subquery %s does not have attribute %d",
rte->eref->aliasname, attnum);
expr = (Node *) ste->expr;
if (IsA(expr, Var))
{
/*
* Recurse into the sub-select to see what its Var refers
* to. We have to build an additional level of ParseState
* to keep in step with varlevelsup in the subselect.
*/
ParseState mypstate = {0};
mypstate.parentParseState = pstate;
mypstate.p_rtable = rte->subquery->rtable;
/* don't bother filling the rest of the fake pstate */
return expandRecordVariable(&mypstate, (Var *) expr, 0);
}
/* else fall through to inspect the expression */
}
break;
case RTE_JOIN:
/* Join RTE --- recursively inspect the alias variable */
Assert(attnum > 0 && attnum <= list_length(rte->joinaliasvars));
expr = (Node *) list_nth(rte->joinaliasvars, attnum - 1);
Assert(expr != NULL);
/* We intentionally don't strip implicit coercions here */
if (IsA(expr, Var))
return expandRecordVariable(pstate, (Var *) expr, netlevelsup);
/* else fall through to inspect the expression */
break;
case RTE_FUNCTION:
/*
* We couldn't get here unless a function is declared with one of
* its result columns as RECORD, which is not allowed.
*/
break;
case RTE_TABLEFUNC:
/*
* Table function cannot have columns with RECORD type.
*/
break;
case RTE_CTE:
/* CTE reference: examine subquery's output expr */
if (!rte->self_reference)
{
CommonTableExpr *cte = GetCTEForRTE(pstate, rte, netlevelsup);
TargetEntry *ste;
ste = get_tle_by_resno(GetCTETargetList(cte), attnum);
if (ste == NULL || ste->resjunk)
elog(ERROR, "CTE %s does not have attribute %d",
rte->eref->aliasname, attnum);
expr = (Node *) ste->expr;
if (IsA(expr, Var))
{
/*
* Recurse into the CTE to see what its Var refers to. We
* have to build an additional level of ParseState to keep
* in step with varlevelsup in the CTE; furthermore it
* could be an outer CTE.
*/
ParseState mypstate;
Index levelsup;
MemSet(&mypstate, 0, sizeof(mypstate));
/* this loop must work, since GetCTEForRTE did */
for (levelsup = 0;
levelsup < rte->ctelevelsup + netlevelsup;
levelsup++)
pstate = pstate->parentParseState;
mypstate.parentParseState = pstate;
mypstate.p_rtable = ((Query *) cte->ctequery)->rtable;
/* don't bother filling the rest of the fake pstate */
return expandRecordVariable(&mypstate, (Var *) expr, 0);
}
/* else fall through to inspect the expression */
}
break;
}
/*
* We now have an expression we can't expand any more, so see if
* get_expr_result_tupdesc() can do anything with it.
*/
return get_expr_result_tupdesc(expr, false);
}
/*
* FigureColname -
* if the name of the resulting column is not specified in the target
* list, we have to guess a suitable name. The SQL spec provides some
* guidance, but not much...
*
* Note that the argument is the *untransformed* parse tree for the target
* item. This is a shade easier to work with than the transformed tree.
*/
char *
FigureColname(Node *node)
{
char *name = NULL;
(void) FigureColnameInternal(node, &name);
if (name != NULL)
return name;
/* default result if we can't guess anything */
return "?column?";
}
/*
* FigureIndexColname -
* choose the name for an expression column in an index
*
* This is actually just like FigureColname, except we return NULL if
* we can't pick a good name.
*/
char *
FigureIndexColname(Node *node)
{
char *name = NULL;
(void) FigureColnameInternal(node, &name);
return name;
}
/*
* FigureColnameInternal -
* internal workhorse for FigureColname
*
* Return value indicates strength of confidence in result:
* 0 - no information
* 1 - second-best name choice
* 2 - good name choice
* The return value is actually only used internally.
* If the result isn't zero, *name is set to the chosen name.
*/
static int
FigureColnameInternal(Node *node, char **name)
{
int strength = 0;
if (node == NULL)
return strength;
switch (nodeTag(node))
{
case T_ColumnRef:
{
char *fname = NULL;
ListCell *l;
/* find last field name, if any, ignoring "*" */
foreach(l, ((ColumnRef *) node)->fields)
{
Node *i = lfirst(l);
if (IsA(i, String))
fname = strVal(i);
}
if (fname)
{
*name = fname;
return 2;
}
}
break;
case T_A_Indirection:
{
A_Indirection *ind = (A_Indirection *) node;
char *fname = NULL;
ListCell *l;
/* find last field name, if any, ignoring "*" and subscripts */
foreach(l, ind->indirection)
{
Node *i = lfirst(l);
if (IsA(i, String))
fname = strVal(i);
}
if (fname)
{
*name = fname;
return 2;
}
return FigureColnameInternal(ind->arg, name);
}
break;
case T_FuncCall:
*name = strVal(llast(((FuncCall *) node)->funcname));
return 2;
case T_A_Expr:
if (((A_Expr *) node)->kind == AEXPR_NULLIF)
{
/* make nullif() act like a regular function */
*name = "nullif";
return 2;
}
break;
case T_TypeCast:
strength = FigureColnameInternal(((TypeCast *) node)->arg,
name);
if (strength <= 1)
{
if (((TypeCast *) node)->typeName != NULL)
{
*name = strVal(llast(((TypeCast *) node)->typeName->names));
return 1;
}
}
break;
case T_CollateClause:
return FigureColnameInternal(((CollateClause *) node)->arg, name);
case T_GroupingFunc:
/* make GROUPING() act like a regular function */
*name = "grouping";
return 2;
case T_SubLink:
switch (((SubLink *) node)->subLinkType)
{
case EXISTS_SUBLINK:
*name = "exists";
return 2;
case ARRAY_SUBLINK:
*name = "array";
return 2;
case EXPR_SUBLINK:
{
/* Get column name of the subquery's single target */
SubLink *sublink = (SubLink *) node;
Query *query = (Query *) sublink->subselect;
/*
* The subquery has probably already been transformed,
* but let's be careful and check that. (The reason
* we can see a transformed subquery here is that
* transformSubLink is lazy and modifies the SubLink
* node in-place.)
*/
if (IsA(query, Query))
{
TargetEntry *te = (TargetEntry *) linitial(query->targetList);
if (te->resname)
{
*name = te->resname;
return 2;
}
}
}
break;
/* As with other operator-like nodes, these have no names */
case MULTIEXPR_SUBLINK:
case ALL_SUBLINK:
case ANY_SUBLINK:
case ROWCOMPARE_SUBLINK:
case CTE_SUBLINK:
break;
}
break;
case T_CaseExpr:
strength = FigureColnameInternal((Node *) ((CaseExpr *) node)->defresult,
name);
if (strength <= 1)
{
*name = "case";
return 1;
}
break;
case T_A_ArrayExpr:
/* make ARRAY[] act like a function */
*name = "array";
return 2;
case T_RowExpr:
/* make ROW() act like a function */
*name = "row";
return 2;
case T_CoalesceExpr:
/* make coalesce() act like a regular function */
*name = "coalesce";
return 2;
case T_MinMaxExpr:
/* make greatest/least act like a regular function */
switch (((MinMaxExpr *) node)->op)
{
case IS_GREATEST:
*name = "greatest";
return 2;
case IS_LEAST:
*name = "least";
return 2;
}
break;
case T_SQLValueFunction:
/* make these act like a function or variable */
switch (((SQLValueFunction *) node)->op)
{
case SVFOP_CURRENT_DATE:
*name = "current_date";
return 2;
case SVFOP_CURRENT_TIME:
case SVFOP_CURRENT_TIME_N:
*name = "current_time";
return 2;
case SVFOP_CURRENT_TIMESTAMP:
case SVFOP_CURRENT_TIMESTAMP_N:
*name = "current_timestamp";
return 2;
case SVFOP_LOCALTIME:
case SVFOP_LOCALTIME_N:
*name = "localtime";
return 2;
case SVFOP_LOCALTIMESTAMP:
case SVFOP_LOCALTIMESTAMP_N:
*name = "localtimestamp";
return 2;
case SVFOP_CURRENT_ROLE:
*name = "current_role";
return 2;
case SVFOP_CURRENT_USER:
*name = "current_user";
return 2;
case SVFOP_USER:
*name = "user";
return 2;
case SVFOP_SESSION_USER:
*name = "session_user";
return 2;
case SVFOP_CURRENT_CATALOG:
*name = "current_catalog";
return 2;
case SVFOP_CURRENT_SCHEMA:
*name = "current_schema";
return 2;
}
break;
case T_XmlExpr:
/* make SQL/XML functions act like a regular function */
switch (((XmlExpr *) node)->op)
{
case IS_XMLCONCAT:
*name = "xmlconcat";
return 2;
case IS_XMLELEMENT:
*name = "xmlelement";
return 2;
case IS_XMLFOREST:
*name = "xmlforest";
return 2;
case IS_XMLPARSE:
*name = "xmlparse";
return 2;
case IS_XMLPI:
*name = "xmlpi";
return 2;
case IS_XMLROOT:
*name = "xmlroot";
return 2;
case IS_XMLSERIALIZE:
*name = "xmlserialize";
return 2;
case IS_DOCUMENT:
/* nothing */
break;
}
break;
case T_XmlSerialize:
*name = "xmlserialize";
return 2;
default:
break;
}
return strength;
}
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