2000-01-06 07:40:54 +01:00
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--
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-- SELECT_DISTINCT_ON
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--
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2000-01-27 19:11:50 +01:00
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SELECT DISTINCT ON (string4) string4, two, ten
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FROM tmp
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ORDER BY string4 using <, two using >, ten using <;
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string4 | two | ten
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---------+-----+-----
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AAAAxx | 1 | 1
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HHHHxx | 1 | 1
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OOOOxx | 1 | 1
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VVVVxx | 1 | 1
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(4 rows)
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-- this will fail due to conflict of ordering requirements
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SELECT DISTINCT ON (string4, ten) string4, two, ten
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FROM tmp
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ORDER BY string4 using <, two using <, ten using <;
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ERROR: SELECT DISTINCT ON expressions must match initial ORDER BY expressions
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2008-09-01 22:42:46 +02:00
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LINE 1: SELECT DISTINCT ON (string4, ten) string4, two, ten
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^
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2000-01-27 19:11:50 +01:00
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SELECT DISTINCT ON (string4, ten) string4, ten, two
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FROM tmp
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ORDER BY string4 using <, ten using >, two using <;
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string4 | ten | two
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---------+-----+-----
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AAAAxx | 9 | 1
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AAAAxx | 8 | 0
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AAAAxx | 7 | 1
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AAAAxx | 6 | 0
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AAAAxx | 5 | 1
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AAAAxx | 4 | 0
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AAAAxx | 3 | 1
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AAAAxx | 2 | 0
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AAAAxx | 1 | 1
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AAAAxx | 0 | 0
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HHHHxx | 9 | 1
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HHHHxx | 8 | 0
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HHHHxx | 7 | 1
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HHHHxx | 6 | 0
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HHHHxx | 5 | 1
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HHHHxx | 4 | 0
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HHHHxx | 3 | 1
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HHHHxx | 2 | 0
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HHHHxx | 1 | 1
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HHHHxx | 0 | 0
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OOOOxx | 9 | 1
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OOOOxx | 8 | 0
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OOOOxx | 7 | 1
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OOOOxx | 6 | 0
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OOOOxx | 5 | 1
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OOOOxx | 4 | 0
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OOOOxx | 3 | 1
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OOOOxx | 2 | 0
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OOOOxx | 1 | 1
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OOOOxx | 0 | 0
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VVVVxx | 9 | 1
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VVVVxx | 8 | 0
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VVVVxx | 7 | 1
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VVVVxx | 6 | 0
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VVVVxx | 5 | 1
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VVVVxx | 4 | 0
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VVVVxx | 3 | 1
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VVVVxx | 2 | 0
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VVVVxx | 1 | 1
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VVVVxx | 0 | 0
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(40 rows)
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1997-04-06 10:29:57 +02:00
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2009-09-12 02:04:59 +02:00
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-- bug #5049: early 8.4.x chokes on volatile DISTINCT ON clauses
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select distinct on (1) floor(random()) as r, f1 from int4_tbl order by 1,2;
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r | f1
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---+-------------
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0 | -2147483647
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(1 row)
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