mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-09-28 00:11:53 +02:00
66e9ee79c7
You can't use relation names alone in the target list, try relation.*
506 lines
12 KiB
C
506 lines
12 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* parse_target.c
|
|
* handle target lists
|
|
*
|
|
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
*
|
|
* IDENTIFICATION
|
|
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.67 2001/05/21 18:42:08 momjian Exp $
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
|
|
#include "postgres.h"
|
|
#include "nodes/makefuncs.h"
|
|
#include "parser/parsetree.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"
|
|
|
|
|
|
static List *ExpandAllTables(ParseState *pstate);
|
|
static char *FigureColname(Node *expr, Node *resval);
|
|
|
|
|
|
/*
|
|
* 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.
|
|
* 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,
|
|
char *colname,
|
|
bool resjunk)
|
|
{
|
|
Oid type_id;
|
|
int32 type_mod;
|
|
Resdom *resnode;
|
|
|
|
/* Transform the node if caller didn't do it already */
|
|
if (expr == NULL)
|
|
expr = transformExpr(pstate, node, EXPR_COLUMN_FIRST);
|
|
|
|
if (IsA(expr, Ident) && ((Ident *)expr)->isRel)
|
|
elog(ERROR,"You can't use relation names alone in the target list, try relation.*.");
|
|
|
|
type_id = exprType(expr);
|
|
type_mod = exprTypmod(expr);
|
|
|
|
if (colname == NULL)
|
|
{
|
|
|
|
/*
|
|
* Generate a suitable column name for a column without any
|
|
* explicit 'AS ColumnName' clause.
|
|
*/
|
|
colname = FigureColname(expr, node);
|
|
}
|
|
|
|
resnode = makeResdom((AttrNumber) pstate->p_last_resno++,
|
|
type_id,
|
|
type_mod,
|
|
colname,
|
|
resjunk);
|
|
|
|
return makeTargetEntry(resnode, expr);
|
|
}
|
|
|
|
|
|
/*
|
|
* transformTargetList()
|
|
* Turns a list of ResTarget's into a list of TargetEntry's.
|
|
*
|
|
* At this point, we don't care whether we are doing SELECT, INSERT,
|
|
* or UPDATE; we just transform the given expressions.
|
|
*/
|
|
List *
|
|
transformTargetList(ParseState *pstate, List *targetlist)
|
|
{
|
|
List *p_target = NIL;
|
|
|
|
while (targetlist != NIL)
|
|
{
|
|
ResTarget *res = (ResTarget *) lfirst(targetlist);
|
|
|
|
if (IsA(res->val, Attr))
|
|
{
|
|
Attr *att = (Attr *) res->val;
|
|
|
|
if (att->relname != NULL && strcmp(att->relname, "*") == 0)
|
|
{
|
|
|
|
/*
|
|
* Target item is a single '*', expand all tables (eg.
|
|
* SELECT * FROM emp)
|
|
*/
|
|
p_target = nconc(p_target,
|
|
ExpandAllTables(pstate));
|
|
}
|
|
else if (att->attrs != NIL &&
|
|
strcmp(strVal(lfirst(att->attrs)), "*") == 0)
|
|
{
|
|
|
|
/*
|
|
* Target item is relation.*, expand that table (eg.
|
|
* SELECT emp.*, dname FROM emp, dept)
|
|
*/
|
|
Node *rteorjoin;
|
|
int sublevels_up;
|
|
|
|
rteorjoin = refnameRangeOrJoinEntry(pstate, att->relname,
|
|
&sublevels_up);
|
|
|
|
if (rteorjoin == NULL)
|
|
{
|
|
rteorjoin = (Node *) addImplicitRTE(pstate, att->relname);
|
|
sublevels_up = 0;
|
|
}
|
|
|
|
if (IsA(rteorjoin, RangeTblEntry))
|
|
p_target = nconc(p_target,
|
|
expandRelAttrs(pstate,
|
|
(RangeTblEntry *) rteorjoin));
|
|
else if (IsA(rteorjoin, JoinExpr))
|
|
p_target = nconc(p_target,
|
|
expandJoinAttrs(pstate,
|
|
(JoinExpr *) rteorjoin,
|
|
sublevels_up));
|
|
else
|
|
elog(ERROR, "transformTargetList: unexpected node type %d",
|
|
nodeTag(rteorjoin));
|
|
}
|
|
else
|
|
{
|
|
/* Plain Attr node, treat it as an expression */
|
|
p_target = lappend(p_target,
|
|
transformTargetEntry(pstate,
|
|
res->val,
|
|
NULL,
|
|
res->name,
|
|
false));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Everything else but Attr */
|
|
p_target = lappend(p_target,
|
|
transformTargetEntry(pstate,
|
|
res->val,
|
|
NULL,
|
|
res->name,
|
|
false));
|
|
}
|
|
|
|
targetlist = lnext(targetlist);
|
|
}
|
|
|
|
return p_target;
|
|
}
|
|
|
|
|
|
/*
|
|
* updateTargetListEntry()
|
|
* This is used in INSERT and UPDATE statements only. It prepares a
|
|
* 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 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 for target column, if any
|
|
*/
|
|
void
|
|
updateTargetListEntry(ParseState *pstate,
|
|
TargetEntry *tle,
|
|
char *colname,
|
|
int attrno,
|
|
List *indirection)
|
|
{
|
|
Oid type_id = exprType(tle->expr); /* type of value provided */
|
|
Oid attrtype; /* type of target column */
|
|
int32 attrtypmod;
|
|
Resdom *resnode = tle->resdom;
|
|
Relation rd = pstate->p_target_relation;
|
|
|
|
Assert(rd != NULL);
|
|
if (attrno <= 0)
|
|
elog(ERROR, "Cannot assign to system attribute '%s'", colname);
|
|
attrtype = attnumTypeId(rd, attrno);
|
|
attrtypmod = rd->rd_att->attrs[attrno - 1]->atttypmod;
|
|
|
|
/*
|
|
* If there are subscripts on the target column, prepare an array
|
|
* assignment expression. This will generate an array value that the
|
|
* source value has been inserted into, which can then be placed in
|
|
* the new tuple constructed by INSERT or UPDATE. Note that
|
|
* transformArraySubscripts takes care of type coercion.
|
|
*/
|
|
if (indirection)
|
|
{
|
|
Node *arrayBase;
|
|
ArrayRef *aref;
|
|
|
|
if (pstate->p_is_insert)
|
|
{
|
|
|
|
/*
|
|
* The command is INSERT INTO table (arraycol[subscripts]) ...
|
|
* so there is not really a source array value to work with.
|
|
* Let the executor do something reasonable, if it can. Notice
|
|
* that we force transformArraySubscripts to treat the
|
|
* subscripting op as an array-slice op below, so the source
|
|
* data will have been coerced to the array type.
|
|
*/
|
|
arrayBase = NULL; /* signal there is no source array */
|
|
}
|
|
else
|
|
{
|
|
|
|
/*
|
|
* Build a Var for the array to be updated.
|
|
*/
|
|
arrayBase = (Node *) make_var(pstate,
|
|
pstate->p_target_rangetblentry,
|
|
attrno);
|
|
}
|
|
|
|
aref = transformArraySubscripts(pstate,
|
|
arrayBase,
|
|
attrtype,
|
|
indirection,
|
|
pstate->p_is_insert,
|
|
tle->expr);
|
|
tle->expr = (Node *) aref;
|
|
}
|
|
else
|
|
{
|
|
|
|
/*
|
|
* For normal non-subscripted target column, do type checking and
|
|
* coercion. But accept InvalidOid, which indicates the source is
|
|
* a NULL constant.
|
|
*/
|
|
if (type_id != InvalidOid)
|
|
{
|
|
if (type_id != attrtype)
|
|
{
|
|
tle->expr = CoerceTargetExpr(pstate, tle->expr, type_id,
|
|
attrtype, attrtypmod);
|
|
if (tle->expr == NULL)
|
|
elog(ERROR, "Attribute '%s' is of type '%s'"
|
|
" but expression is of type '%s'"
|
|
"\n\tYou will need to rewrite or cast the expression",
|
|
colname,
|
|
typeidTypeName(attrtype),
|
|
typeidTypeName(type_id));
|
|
}
|
|
|
|
/*
|
|
* If the target is a fixed-length type, it may need a length
|
|
* coercion as well as a type coercion.
|
|
*/
|
|
tle->expr = coerce_type_typmod(pstate, tle->expr,
|
|
attrtype, attrtypmod);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The result of the target expression should now match the
|
|
* destination column's type. Also, reset the resname and resno to
|
|
* identify the destination column --- rewriter and planner depend on
|
|
* that!
|
|
*/
|
|
resnode->restype = attrtype;
|
|
resnode->restypmod = attrtypmod;
|
|
resnode->resname = colname;
|
|
resnode->resno = (AttrNumber) attrno;
|
|
}
|
|
|
|
|
|
Node *
|
|
CoerceTargetExpr(ParseState *pstate,
|
|
Node *expr,
|
|
Oid type_id,
|
|
Oid attrtype,
|
|
int32 attrtypmod)
|
|
{
|
|
if (can_coerce_type(1, &type_id, &attrtype))
|
|
expr = coerce_type(pstate, expr, type_id, attrtype, attrtypmod);
|
|
|
|
#ifndef DISABLE_STRING_HACKS
|
|
|
|
/*
|
|
* string hacks to get transparent conversions w/o explicit
|
|
* conversions
|
|
*/
|
|
else if ((attrtype == BPCHAROID) || (attrtype == VARCHAROID))
|
|
{
|
|
Oid text_id = TEXTOID;
|
|
|
|
if (type_id == TEXTOID)
|
|
{
|
|
}
|
|
else if (can_coerce_type(1, &type_id, &text_id))
|
|
expr = coerce_type(pstate, expr, type_id, text_id, attrtypmod);
|
|
else
|
|
expr = NULL;
|
|
}
|
|
#endif
|
|
|
|
else
|
|
expr = NULL;
|
|
|
|
return expr;
|
|
}
|
|
|
|
|
|
/*
|
|
* checkInsertTargets -
|
|
* generate a list of column names 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.
|
|
* (used exclusively for inserts)
|
|
*/
|
|
List *
|
|
checkInsertTargets(ParseState *pstate, List *cols, List **attrnos)
|
|
{
|
|
*attrnos = NIL;
|
|
|
|
if (cols == NIL)
|
|
{
|
|
|
|
/*
|
|
* Generate default column list for INSERT.
|
|
*/
|
|
Form_pg_attribute *attr = pstate->p_target_relation->rd_att->attrs;
|
|
int numcol = pstate->p_target_relation->rd_rel->relnatts;
|
|
int i;
|
|
|
|
for (i = 0; i < numcol; i++)
|
|
{
|
|
Ident *id = makeNode(Ident);
|
|
|
|
#ifdef _DROP_COLUMN_HACK__
|
|
if (COLUMN_IS_DROPPED(attr[i]))
|
|
continue;
|
|
#endif /* _DROP_COLUMN_HACK__ */
|
|
id->name = palloc(NAMEDATALEN);
|
|
StrNCpy(id->name, NameStr(attr[i]->attname), NAMEDATALEN);
|
|
id->indirection = NIL;
|
|
id->isRel = false;
|
|
cols = lappend(cols, id);
|
|
*attrnos = lappendi(*attrnos, i + 1);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
|
|
/*
|
|
* Do initial validation of user-supplied INSERT column list.
|
|
*/
|
|
List *tl;
|
|
|
|
foreach(tl, cols)
|
|
{
|
|
char *name = ((Ident *) lfirst(tl))->name;
|
|
int attrno;
|
|
|
|
/* Lookup column name, elog on failure */
|
|
attrno = attnameAttNum(pstate->p_target_relation, name);
|
|
/* Check for duplicates */
|
|
if (intMember(attrno, *attrnos))
|
|
elog(ERROR, "Attribute '%s' specified more than once", name);
|
|
*attrnos = lappendi(*attrnos, attrno);
|
|
}
|
|
}
|
|
|
|
return cols;
|
|
}
|
|
|
|
/* ExpandAllTables()
|
|
* Turns '*' (in the target list) into a list of targetlist entries.
|
|
*
|
|
* tlist entries are generated for each relation appearing at the top level
|
|
* of the query's namespace, except for RTEs marked not inFromCl. (These
|
|
* may include NEW/OLD pseudo-entries, implicit RTEs, etc.)
|
|
*/
|
|
static List *
|
|
ExpandAllTables(ParseState *pstate)
|
|
{
|
|
List *target = NIL;
|
|
List *ns;
|
|
|
|
foreach(ns, pstate->p_namespace)
|
|
{
|
|
Node *n = (Node *) lfirst(ns);
|
|
|
|
if (IsA(n, RangeTblRef))
|
|
{
|
|
RangeTblEntry *rte;
|
|
|
|
rte = rt_fetch(((RangeTblRef *) n)->rtindex,
|
|
pstate->p_rtable);
|
|
|
|
/*
|
|
* Ignore added-on relations that were not listed in the FROM
|
|
* clause.
|
|
*/
|
|
if (!rte->inFromCl)
|
|
continue;
|
|
|
|
target = nconc(target, expandRelAttrs(pstate, rte));
|
|
}
|
|
else if (IsA(n, JoinExpr))
|
|
{
|
|
/* A newfangled join expression */
|
|
JoinExpr *j = (JoinExpr *) n;
|
|
|
|
/* Currently, a join expr could only have come from FROM. */
|
|
target = nconc(target, expandJoinAttrs(pstate, j, 0));
|
|
}
|
|
else
|
|
elog(ERROR, "ExpandAllTables: unexpected node (internal error)"
|
|
"\n\t%s", nodeToString(n));
|
|
}
|
|
|
|
/* Check for SELECT *; */
|
|
if (target == NIL)
|
|
elog(ERROR, "Wildcard with no tables specified not allowed");
|
|
|
|
return target;
|
|
}
|
|
|
|
/*
|
|
* 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...
|
|
*
|
|
*/
|
|
static char *
|
|
FigureColname(Node *expr, Node *resval)
|
|
{
|
|
/* Some of these are easiest to do with the untransformed node */
|
|
switch (nodeTag(resval))
|
|
{
|
|
case T_Ident:
|
|
return ((Ident *) resval)->name;
|
|
case T_Attr:
|
|
{
|
|
List *attrs = ((Attr *) resval)->attrs;
|
|
|
|
if (attrs)
|
|
{
|
|
while (lnext(attrs) != NIL)
|
|
attrs = lnext(attrs);
|
|
return strVal(lfirst(attrs));
|
|
}
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
/* Otherwise, work with the transformed node */
|
|
switch (nodeTag(expr))
|
|
{
|
|
case T_Expr:
|
|
if (((Expr *) expr)->opType == FUNC_EXPR && IsA(resval, FuncCall))
|
|
return ((FuncCall *) resval)->funcname;
|
|
break;
|
|
case T_Aggref:
|
|
return ((Aggref *) expr)->aggname;
|
|
case T_CaseExpr:
|
|
{
|
|
char *name;
|
|
|
|
name = FigureColname(((CaseExpr *) expr)->defresult, resval);
|
|
if (strcmp(name, "?column?") == 0)
|
|
name = "case";
|
|
return name;
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return "?column?";
|
|
}
|