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Fix display of whole-row Var appearing at the top level of a SELECT list.

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While we normally prefer the notation "foo.*" for a whole-row Var, that does
not work at SELECT top level, because in that context the parser will assume
that what is wanted is to expand the "*" into a list of separate target
columns, yielding behavior different from a whole-row Var.  We have to emit
just "foo" instead in that context.  Per report from Sokolov Yura.
This commit is contained in:
Tom Lane 2006-01-26 17:08:19 +00:00
parent 97ec950186
commit ec057a4380
1 changed files with 56 additions and 25 deletions
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81
src/backend/utils/adt/ruleutils.c
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@ -3,7 +3,7 @@
* back to source text
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.212 2005/12/30 18:34:22 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.213 2006/01/26 17:08:19 tgl Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@ -2018,6 +2018,7 @@ get_basic_select_query(Query *query, deparse_context *context,
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
char *colname;
char *attname;
if (tle->resjunk)
continue; /* ignore junk entries */
@ -2026,7 +2027,55 @@ get_basic_select_query(Query *query, deparse_context *context,
sep = ", ";
colno++;
get_rule_expr((Node *) tle->expr, context, true);
/*
* We special-case Var nodes rather than using get_rule_expr.
* This is needed because get_rule_expr will display a whole-row Var
* as "foo.*", which is the preferred notation in most contexts, but
* at the top level of a SELECT list it's not right (the parser will
* expand that notation into multiple columns, yielding behavior
* different from a whole-row Var). We want just "foo", instead.
*/
if (tle->expr && IsA(tle->expr, Var))
{
Var *var = (Var *) (tle->expr);
char *schemaname;
char *refname;
get_names_for_var(var, 0, context,
&schemaname, &refname, &attname);
if (refname && (context->varprefix || attname == NULL))
{
if (schemaname)
appendStringInfo(buf, "%s.",
quote_identifier(schemaname));
if (strcmp(refname, "*NEW*") == 0)
appendStringInfoString(buf, "new");
else if (strcmp(refname, "*OLD*") == 0)
appendStringInfoString(buf, "old");
else
appendStringInfoString(buf, quote_identifier(refname));
if (attname)
appendStringInfoChar(buf, '.');
}
if (attname)
appendStringInfoString(buf, quote_identifier(attname));
else
{
/*
* In the whole-row Var case, refname is what the default AS
* name would be.
*/
attname = refname;
}
}
else
{
get_rule_expr((Node *) tle->expr, context, true);
/* We'll show the AS name unless it's this: */
attname = "?column?";
}
/*
* Figure out what the result column should be called. In the context
@ -2039,28 +2088,10 @@ get_basic_select_query(Query *query, deparse_context *context,
else
colname = tle->resname;
/* Show AS unless the column's name is correct as-is */
if (colname) /* resname could be NULL */
{
/* Check if we must say AS ... */
bool tell_as;
if (!IsA(tle->expr, Var))
tell_as = (strcmp(colname, "?column?") != 0);
else
{
Var *var = (Var *) (tle->expr);
char *schemaname;
char *refname;
char *attname;
get_names_for_var(var, 0, context,
&schemaname, &refname, &attname);
tell_as = (attname == NULL ||
strcmp(attname, colname) != 0);
}
/* and do if so */
if (tell_as)
if (attname == NULL || strcmp(attname, colname) != 0)
appendStringInfo(buf, " AS %s", quote_identifier(colname));
}
}
@ -3098,9 +3129,9 @@ get_rule_expr(Node *node, deparse_context *context,
quote_identifier(schemaname));
if (strcmp(refname, "*NEW*") == 0)
appendStringInfo(buf, "new.");
appendStringInfoString(buf, "new.");
else if (strcmp(refname, "*OLD*") == 0)
appendStringInfo(buf, "old.");
appendStringInfoString(buf, "old.");
else
appendStringInfo(buf, "%s.",
quote_identifier(refname));
@ -3108,7 +3139,7 @@ get_rule_expr(Node *node, deparse_context *context,
if (attname)
appendStringInfoString(buf, quote_identifier(attname));
else
appendStringInfo(buf, "*");
appendStringInfoString(buf, "*");
}
break;