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Carry column aliases from the parser frontend. Enables queries like

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SELECT a FROM t1 tx (a);
Allow join syntax, including queries like
  SELECT * FROM t1 NATURAL JOIN t2;
Update RTE structure to hold column aliases in an Attr structure.
This commit is contained in:
Thomas G. Lockhart
2000-02-15 03:38:29 +00:00
parent 92c8437d8d
commit a344a6e7b5
27 changed files with 1102 additions and 324 deletions
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55
src/backend/parser/parse_target.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.54 2000/01/26 05:56:42 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.55 2000/02/15 03:37:47 thomas Exp $
*
*-------------------------------------------------------------------------
*/
@ -105,8 +105,35 @@ transformTargetList(ParseState *pstate, List *targetlist)
* Target item is a single '*', expand all tables
* (eg. SELECT * FROM emp)
*/
p_target = nconc(p_target,
ExpandAllTables(pstate));
if (pstate->p_shape != NULL)
{
List *s, *a;
int i;
Assert(length(pstate->p_shape) == length(pstate->p_alias));
s = pstate->p_shape;
a = pstate->p_alias;
for (i = 0; i < length(pstate->p_shape); i++)
{
TargetEntry *te;
char *colname;
Attr *shape = lfirst(s);
Attr *alias = lfirst(a);
Assert(IsA(shape, Attr) && IsA(alias, Attr));
colname = strVal(lfirst(alias->attrs));
te = transformTargetEntry(pstate, (Node *) shape,
NULL, colname, false);
p_target = lappend(p_target, te);
s = lnext(s);
a = lnext(a);
}
}
else
p_target = nconc(p_target,
ExpandAllTables(pstate));
}
else if (att->attrs != NIL &&
strcmp(strVal(lfirst(att->attrs)), "*") == 0)
@ -116,9 +143,8 @@ transformTargetList(ParseState *pstate, List *targetlist)
* (eg. SELECT emp.*, dname FROM emp, dept)
*/
p_target = nconc(p_target,
expandAll(pstate,
att->relname,
att->relname,
expandAll(pstate, att->relname,
makeAttr(att->relname, NULL),
&pstate->p_last_resno));
}
else
@ -192,12 +218,18 @@ updateTargetListEntry(ParseState *pstate,
*/
if (indirection)
{
#ifndef DISABLE_JOIN_SYNTAX
Attr *att = makeAttr(pstrdup(RelationGetRelationName(rd)), colname);
#else
Attr *att = makeNode(Attr);
#endif
Node *arrayBase;
ArrayRef *aref;
#ifdef DISABLE_JOIN_SYNTAX
att->relname = pstrdup(RelationGetRelationName(rd));
att->attrs = lcons(makeString(colname), NIL);
#endif
arrayBase = ParseNestedFuncOrColumn(pstate, att,
&pstate->p_last_resno,
EXPR_COLUMN_FIRST);
@ -355,10 +387,9 @@ checkInsertTargets(ParseState *pstate, List *cols, List **attrnos)
return cols;
}
/*
* ExpandAllTables -
* turns '*' (in the target list) into a list of attributes
* (of all relations in the range table)
/* ExpandAllTables()
* Turns '*' (in the target list) into a list of attributes
* (of all relations in the range table)
*/
static List *
ExpandAllTables(ParseState *pstate)
@ -378,7 +409,7 @@ ExpandAllTables(ParseState *pstate)
/* SELECT *; */
if (rtable == NIL)
elog(ERROR, "Wildcard with no tables specified.");
elog(ERROR, "Wildcard with no tables specified not allowed");
foreach(rt, rtable)
{
@ -393,7 +424,7 @@ ExpandAllTables(ParseState *pstate)
continue;
target = nconc(target,
expandAll(pstate, rte->relname, rte->refname,
expandAll(pstate, rte->ref->relname, rte->ref,
&pstate->p_last_resno));
}
return target;