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，所以它可能是帮助。使用Firebird，我想使用UNION ALL合并两个查询的结果，然后对给定列上的结果输出进行排序。类似：

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

括号来自有效的语法其他数据库，并且需要确保UNION ALL（定义为在表上工作的操作，即无序记录集）的参数不尝试单独排序。但是我无法得到这个语法在Firebird中工作 - 怎么办呢？

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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