76 lines
1.8 KiB
Plaintext
76 lines
1.8 KiB
Plaintext
--
|
|
-- SELECT_DISTINCT_ON
|
|
--
|
|
SELECT DISTINCT ON (string4) string4, two, ten
|
|
FROM tmp
|
|
ORDER BY string4 using <, two using >, ten using <;
|
|
string4 | two | ten
|
|
---------+-----+-----
|
|
AAAAxx | 1 | 1
|
|
HHHHxx | 1 | 1
|
|
OOOOxx | 1 | 1
|
|
VVVVxx | 1 | 1
|
|
(4 rows)
|
|
|
|
-- this will fail due to conflict of ordering requirements
|
|
SELECT DISTINCT ON (string4, ten) string4, two, ten
|
|
FROM tmp
|
|
ORDER BY string4 using <, two using <, ten using <;
|
|
ERROR: SELECT DISTINCT ON expressions must match initial ORDER BY expressions
|
|
LINE 1: SELECT DISTINCT ON (string4, ten) string4, two, ten
|
|
^
|
|
SELECT DISTINCT ON (string4, ten) string4, ten, two
|
|
FROM tmp
|
|
ORDER BY string4 using <, ten using >, two using <;
|
|
string4 | ten | two
|
|
---------+-----+-----
|
|
AAAAxx | 9 | 1
|
|
AAAAxx | 8 | 0
|
|
AAAAxx | 7 | 1
|
|
AAAAxx | 6 | 0
|
|
AAAAxx | 5 | 1
|
|
AAAAxx | 4 | 0
|
|
AAAAxx | 3 | 1
|
|
AAAAxx | 2 | 0
|
|
AAAAxx | 1 | 1
|
|
AAAAxx | 0 | 0
|
|
HHHHxx | 9 | 1
|
|
HHHHxx | 8 | 0
|
|
HHHHxx | 7 | 1
|
|
HHHHxx | 6 | 0
|
|
HHHHxx | 5 | 1
|
|
HHHHxx | 4 | 0
|
|
HHHHxx | 3 | 1
|
|
HHHHxx | 2 | 0
|
|
HHHHxx | 1 | 1
|
|
HHHHxx | 0 | 0
|
|
OOOOxx | 9 | 1
|
|
OOOOxx | 8 | 0
|
|
OOOOxx | 7 | 1
|
|
OOOOxx | 6 | 0
|
|
OOOOxx | 5 | 1
|
|
OOOOxx | 4 | 0
|
|
OOOOxx | 3 | 1
|
|
OOOOxx | 2 | 0
|
|
OOOOxx | 1 | 1
|
|
OOOOxx | 0 | 0
|
|
VVVVxx | 9 | 1
|
|
VVVVxx | 8 | 0
|
|
VVVVxx | 7 | 1
|
|
VVVVxx | 6 | 0
|
|
VVVVxx | 5 | 1
|
|
VVVVxx | 4 | 0
|
|
VVVVxx | 3 | 1
|
|
VVVVxx | 2 | 0
|
|
VVVVxx | 1 | 1
|
|
VVVVxx | 0 | 0
|
|
(40 rows)
|
|
|
|
-- bug #5049: early 8.4.x chokes on volatile DISTINCT ON clauses
|
|
select distinct on (1) floor(random()) as r, f1 from int4_tbl order by 1,2;
|
|
r | f1
|
|
---+-------------
|
|
0 | -2147483647
|
|
(1 row)
|
|
|