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PSQL:行数连续递增

row-number psql

0

klaus · 技术社区 · 7 年前

嗨,有以下表格:

 field1 | field3
--------+--------
 A1     | foo
 A2     | v1
 A3     | v2
 A4     | bar

 field2 | field3 
--------+--------
 B1     | foo 
 B2     | bar

如果我提出以下要求:

SELECT DISTINCT ON (T2.field2, T2.field3)
  T2.field2 AS F2,
  T2.field3 AS F3,
  ROW_NUMBER () OVER (ORDER BY T2.field3) AS F4
FROM T2
JOIN T1 ON T2.field3=T1.field3

... 我得到以下结果:

F2:B1, F3:foo, F4:1
F2:B2, F3:bar, F4:4 // I would like F4:2

但我希望F4一个一个递增。。。我认为这是因为T1的连接,但我不知道如何隔离行\号。。。

1 回复 | 直到 7 年前

1

Pavan Katepalli 7 年前

作品

SELECT DISTINCT ON (T2.field2, T2.field3)
  T2.field2 AS F2,
  T2.field3 AS F3,
  ROW_NUMBER () OVER (ORDER BY T2.field3 DESC) AS F4
FROM T2
JOIN T1 ON T2.field3=T1.field3;

同样有效以及密级()不会重复计算

在这里的第302行,我讨论了为什么我使用密集秩而不是行数或秩 https://github.com/pavankat/fantasy-football/blob/master/db/queries.sql

SELECT DISTINCT ON (T2.field2, T2.field3)
  T2.field2 AS F2,
  T2.field3 AS F3,
  DENSE_RANK() OVER (ORDER BY T2.field3 DESC) AS F4
FROM T2
JOIN T1 ON T2.field3=T1.field3;