在 Firebird 中结合 UNION ALL 和 ORDER BY [英] Combining UNION ALL and ORDER BY in Firebird

问题描述

这是我第一次尝试回答我自己的问题，因为有人可能会遇到这个问题，所以它可能会有所帮助.使用 Firebird，我想使用 UNION ALL 组合两个查询的结果，然后在给定的列上对结果输出进行排序.类似的东西:

This is my first attempt at answering my own question, since someone may well run into this and so it might be of help. Using Firebird, I want to combine the results of two queries using UNION ALL, then sort the resulting output on a given column. Something like:

(select C1, C2, C3 from T1)
union all 
(select C1, C2, C3 from T2)
order by C3

括号来自其他数据库的有效语法，需要确保 UNION ALL(定义为在表上工作的操作 - 即 无序 记录集)的参数不'尝试单独订购.但是，我无法在 Firebird 中使用此语法 - 怎么做?

The parentheses came from valid syntax for other databases, and are needed to make sure the arguments to UNION ALL (an operation that's defined to work on tables - i.e. an unordered set of records) don't try to be ordered individually. However I couldn't get this syntax to work in Firebird - how can it be done?

推荐答案

SELECT C1, C2, C3
FROM (
    select C1, C2, C3 from T1
    union all 
    select C1, C2, C3 from T2
)
order by C3

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