SQL查询-在UNION中使用Order By [英] SQL Query - Using Order By in UNION

问题描述

从两个表中提取数据时，如何以编程方式对联合查询进行排序?例如，

How can one programmatically sort a union query when pulling data from two tables? For example,

SELECT table1.field1 FROM table1 ORDER BY table1.field1
UNION
SELECT table2.field1 FROM table2 ORDER BY table2.field1

引发异常

注意:这是在MS Access Jet数据库引擎上尝试的

Note: this is being attempted on MS Access Jet database engine

推荐答案

有时，您需要在每个需要与UNION结合的部分中使用ORDER BY.

Sometimes you need to have the ORDER BY in each of the sections that need to be combined with UNION.

在这种情况下

SELECT * FROM 
(
  SELECT table1.field1 FROM table1 ORDER BY table1.field1
) DUMMY_ALIAS1

UNION ALL

SELECT * FROM
( 
  SELECT table2.field1 FROM table2 ORDER BY table2.field1
) DUMMY_ALIAS2

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