1
0
mirror of https://github.com/postgres/postgres.git synced 2025-07-09 22:41:56 +03:00

Repair longstanding violation of SQL92 semantics: GROUP BY would

interpret a column name as an output column alias (targetlist AS name),
ather than a real column name as it ought to.  According to the spec,
only ORDER BY should look at output column names.  I left in GROUP BY's
willingness to use an output column number ('GROUP BY 2'), even though
this is also contrary to the spec --- again, only ORDER BY is supposed
to accept that.  But there is no possible reason to want to GROUP BY
an integer constant, so keeping this old behavior won't break any
SQL-compliant queries.  DISTINCT ON will behave the same as GROUP BY.

Change numerology regress test, which depended on the incorrect
behavior.
This commit is contained in:
Tom Lane
2000-02-19 23:45:07 +00:00
parent b48f983ec3
commit 751a14e60c
3 changed files with 40 additions and 26 deletions

View File

@ -88,7 +88,7 @@ SELECT DISTINCT f1 AS two FROM TEMP_GROUP;
SELECT f1 AS two, max(f3) AS max_float, min(f3) as min_float
FROM TEMP_GROUP
GROUP BY two
GROUP BY f1
ORDER BY two, max_float, min_float;
two | max_float | min_float
-----+----------------------+-----------------------
@ -96,19 +96,17 @@ SELECT f1 AS two, max(f3) AS max_float, min(f3) as min_float
2 | 0 | -1.2345678901234e+200
(2 rows)
-- Postgres used to accept this, but it is clearly against SQL92 to
-- interpret GROUP BY arguments as result column names; they should
-- be source column names *only*. An error is expected.
SELECT f1 AS two, max(f3) AS max_float, min(f3) AS min_float
FROM TEMP_GROUP
GROUP BY two
ORDER BY two, max_float, min_float;
two | max_float | min_float
-----+----------------------+-----------------------
1 | 1.2345678901234e+200 | 0
2 | 0 | -1.2345678901234e+200
(2 rows)
ERROR: Attribute 'two' not found
SELECT f1 AS two, (max(f3) + 1) AS max_plus_1, (min(f3) - 1) AS min_minus_1
FROM TEMP_GROUP
GROUP BY two
GROUP BY f1
ORDER BY two, min_minus_1;
two | max_plus_1 | min_minus_1
-----+----------------------+-----------------------
@ -116,14 +114,16 @@ SELECT f1 AS two, (max(f3) + 1) AS max_plus_1, (min(f3) - 1) AS min_minus_1
2 | 1 | -1.2345678901234e+200
(2 rows)
SELECT f1 AS two, (max(f3) + 1) AS max_plus_1, (min(f3) - 1) AS min_minus_1
SELECT f1 AS two,
max(f2) + min(f2) AS max_plus_min,
min(f3) - 1 AS min_minus_1
FROM TEMP_GROUP
GROUP BY two
GROUP BY f1
ORDER BY two, min_minus_1;
two | max_plus_1 | min_minus_1
-----+----------------------+-----------------------
1 | 1.2345678901234e+200 | -1
2 | 1 | -1.2345678901234e+200
two | max_plus_min | min_minus_1
-----+--------------+-----------------------
1 | 0 | -1
2 | 0 | -1.2345678901234e+200
(2 rows)
DROP TABLE TEMP_INT2;

View File

@ -67,9 +67,12 @@ SELECT DISTINCT f1 AS two FROM TEMP_GROUP;
SELECT f1 AS two, max(f3) AS max_float, min(f3) as min_float
FROM TEMP_GROUP
GROUP BY two
GROUP BY f1
ORDER BY two, max_float, min_float;
-- Postgres used to accept this, but it is clearly against SQL92 to
-- interpret GROUP BY arguments as result column names; they should
-- be source column names *only*. An error is expected.
SELECT f1 AS two, max(f3) AS max_float, min(f3) AS min_float
FROM TEMP_GROUP
GROUP BY two
@ -77,12 +80,14 @@ SELECT f1 AS two, max(f3) AS max_float, min(f3) AS min_float
SELECT f1 AS two, (max(f3) + 1) AS max_plus_1, (min(f3) - 1) AS min_minus_1
FROM TEMP_GROUP
GROUP BY two
GROUP BY f1
ORDER BY two, min_minus_1;
SELECT f1 AS two, (max(f3) + 1) AS max_plus_1, (min(f3) - 1) AS min_minus_1
SELECT f1 AS two,
max(f2) + min(f2) AS max_plus_min,
min(f3) - 1 AS min_minus_1
FROM TEMP_GROUP
GROUP BY two
GROUP BY f1
ORDER BY two, min_minus_1;
DROP TABLE TEMP_INT2;