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Allow OLD and NEW in multi-row VALUES within rules.

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Now that we have LATERAL, it's fairly painless to allow this case, which
was left as a TODO in the original multi-row VALUES implementation.
This commit is contained in:
Tom Lane
2012-08-19 14:12:16 -04:00
parent c246eb5aaf
commit 092d7ded29
8 changed files with 164 additions and 47 deletions
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57
src/backend/utils/adt/ruleutils.c
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@ -2919,11 +2919,48 @@ get_select_query_def(Query *query, deparse_context *context,
context->windowTList = save_windowtlist;
}
/*
* Detect whether query looks like SELECT ... FROM VALUES();
* if so, return the VALUES RTE. Otherwise return NULL.
*/
static RangeTblEntry *
get_simple_values_rte(Query *query)
{
RangeTblEntry *result = NULL;
ListCell *lc;
/*
* We want to return TRUE even if the Query also contains OLD or NEW rule
* RTEs. So the idea is to scan the rtable and see if there is only one
* inFromCl RTE that is a VALUES RTE. We don't look at the targetlist at
* all. This is okay because parser/analyze.c will never generate a
* "bare" VALUES RTE --- they only appear inside auto-generated
* sub-queries with very restricted structure.
*/
foreach(lc, query->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
if (rte->rtekind == RTE_VALUES && rte->inFromCl)
{
if (result)
return NULL; /* multiple VALUES (probably not possible) */
result = rte;
}
else if (rte->rtekind == RTE_RELATION && !rte->inFromCl)
continue; /* ignore rule entries */
else
return NULL; /* something else -> not simple VALUES */
}
return result;
}
static void
get_basic_select_query(Query *query, deparse_context *context,
TupleDesc resultDesc)
{
StringInfo buf = context->buf;
RangeTblEntry *values_rte;
char *sep;
ListCell *l;
@ -2936,23 +2973,13 @@ get_basic_select_query(Query *query, deparse_context *context,
/*
* If the query looks like SELECT * FROM (VALUES ...), then print just the
* VALUES part. This reverses what transformValuesClause() did at parse
* time. If the jointree contains just a single VALUES RTE, we assume
* this case applies (without looking at the targetlist...)
* time.
*/
if (list_length(query->jointree->fromlist) == 1)
values_rte = get_simple_values_rte(query);
if (values_rte)
{
RangeTblRef *rtr = (RangeTblRef *) linitial(query->jointree->fromlist);
if (IsA(rtr, RangeTblRef))
{
RangeTblEntry *rte = rt_fetch(rtr->rtindex, query->rtable);
if (rte->rtekind == RTE_VALUES)
{
get_values_def(rte->values_lists, context);
return;
}
}
get_values_def(values_rte->values_lists, context);
return;
}
/*