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Re-allow SRFs and window functions within sub-selects within aggregates.

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check_agg_arguments_walker threw an error upon seeing a SRF or window
function, but that is too aggressive: if the function is within a
sub-select then it's perfectly fine.  I broke the SRF case in commit
0436f6bde by copying the logic for window functions ... but that was
broken too, and had been since commit eaccfded9.

Repair both cases in HEAD, and the window function case back to 9.3.
9.2 gets this right.
This commit is contained in:
Tom Lane
2017-06-27 17:51:11 -04:00
parent 2710ccd782
commit 9c7dc89282
3 changed files with 42 additions and 15 deletions
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37
src/backend/parser/parse_agg.c
View File

@@ -705,21 +705,28 @@ check_agg_arguments_walker(Node *node,
} }
/* Continue and descend into subtree */ /* Continue and descend into subtree */
} }
/* We can throw error on sight for a set-returning function */
if ((IsA(node, FuncExpr) &&((FuncExpr *) node)->funcretset) || /*
(IsA(node, OpExpr) &&((OpExpr *) node)->opretset)) * SRFs and window functions can be rejected immediately, unless we are
ereport(ERROR, * within a sub-select within the aggregate's arguments; in that case
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), * they're OK.
errmsg("aggregate function calls cannot contain set-returning function calls"), */
errhint("You might be able to move the set-returning function into a LATERAL FROM item."), if (context->sublevels_up == 0)
parser_errposition(context->pstate, exprLocation(node)))); {
/* We can throw error on sight for a window function */ if ((IsA(node, FuncExpr) &&((FuncExpr *) node)->funcretset) ||
if (IsA(node, WindowFunc)) (IsA(node, OpExpr) &&((OpExpr *) node)->opretset))
ereport(ERROR, ereport(ERROR,
(errcode(ERRCODE_GROUPING_ERROR), (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("aggregate function calls cannot contain window function calls"), errmsg("aggregate function calls cannot contain set-returning function calls"),
parser_errposition(context->pstate, errhint("You might be able to move the set-returning function into a LATERAL FROM item."),
((WindowFunc *) node)->location))); parser_errposition(context->pstate, exprLocation(node))));
if (IsA(node, WindowFunc))
ereport(ERROR,
(errcode(ERRCODE_GROUPING_ERROR),
errmsg("aggregate function calls cannot contain window function calls"),
parser_errposition(context->pstate,
((WindowFunc *) node)->location)));
}
if (IsA(node, Query)) if (IsA(node, Query))
{ {
/* Recurse into subselects */ /* Recurse into subselects */

14
src/test/regress/expected/tsrf.out
View File

@@ -212,6 +212,20 @@ ERROR: aggregate function calls cannot contain set-returning function calls
LINE 1: SELECT min(generate_series(1, 3)) FROM few; LINE 1: SELECT min(generate_series(1, 3)) FROM few;
^ ^
HINT: You might be able to move the set-returning function into a LATERAL FROM item. HINT: You might be able to move the set-returning function into a LATERAL FROM item.
-- ... unless they're within a sub-select
SELECT sum((3 = ANY(SELECT generate_series(1,4)))::int);
sum
-----
1
(1 row)
SELECT sum((3 = ANY(SELECT lag(x) over(order by x)
FROM generate_series(1,4) x))::int);
sum
-----
1
(1 row)
-- SRFs are not allowed in window function arguments, either -- SRFs are not allowed in window function arguments, either
SELECT min(generate_series(1, 3)) OVER() FROM few; SELECT min(generate_series(1, 3)) OVER() FROM few;
ERROR: window function calls cannot contain set-returning function calls ERROR: window function calls cannot contain set-returning function calls

6
src/test/regress/sql/tsrf.sql
View File

@@ -61,6 +61,12 @@ SELECT q1, coalesce(generate_series(1,3), 0) FROM int8_tbl;
-- SRFs are not allowed in aggregate arguments -- SRFs are not allowed in aggregate arguments
SELECT min(generate_series(1, 3)) FROM few; SELECT min(generate_series(1, 3)) FROM few;
-- ... unless they're within a sub-select
SELECT sum((3 = ANY(SELECT generate_series(1,4)))::int);
SELECT sum((3 = ANY(SELECT lag(x) over(order by x)
FROM generate_series(1,4) x))::int);
-- SRFs are not allowed in window function arguments, either -- SRFs are not allowed in window function arguments, either
SELECT min(generate_series(1, 3)) OVER() FROM few; SELECT min(generate_series(1, 3)) OVER() FROM few;