在没有ANY()的情况下，这是最便宜的聚合函数 [英] Which is the least expensive aggregate function in the absence of ANY()

问题描述

如果DBMS没有ANY()聚合函数，我通常使用MAX()或MIN().

I usally use MAX() or MIN() if a DBMS hasn't an ANY() aggregate function.

mySQL和MS-SQL中有便宜些的东西吗?

Is there something less expensive in mySQL and MS-SQL?

推荐答案

MySQL不需要不需要 ANY()聚合.

MySQL does not need an ANY() aggregate.

如果我做

SELECT field1, field2, SUM(field3) FROM table1 
GROUP BY field2

Microsoft的T-SQL会抱怨，但是

Microsofts T-SQL will complain but

MySQL只会默默执行

MySQL will just silently execute

SELECT whatever(field1), field2, SUM(.... 

当然比SELECT max(field1), field2, SUM(.... GROUP BY field2

MySQL支持ANY，但是SELECT ANY(field1) ...不起作用，因为ANY是类似于IN和ALL的运算符.
参见: http://dev.mysql.com /doc/refman/5.0/en/any-in-some-subqueries.html

MySQL supports ANY, but SELECT ANY(field1) ... doesn't work because ANY is an operator similar to IN and ALL.
see: http://dev.mysql.com/doc/refman/5.0/en/any-in-some-subqueries.html

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