检查两个“选择"是否等效 [英] Check if two "select"s are equivalent

问题描述

有没有一种方法可以检查两个(非平凡的)选择是否等效?

Is there a way to check if two (non-trivial) select are equivalent?

最初，我希望两个选择在形式上等效，但是答案在 proving-sql-query-equivalency 阻止我.

Initially I was hoping for a formally equivalence between two selects, but the answers in proving-sql-query-equivalency stop me.

对于我的实际需要，我可以检查两个选择的(实际)结果是否相同.

For my actual need I can just check if the (actual) results of two selects are the same.

推荐答案

如果要比较查询结果，请尝试以下操作:

If you want to compare the query results try the following:

(select * from query1 MINUS select * from query2) 
UNION ALL
(select * from query2 MINUS select * from query1)

这将导致仅查询之一返回的所有行.

This will result in all rows that are returned by only one of the queries.

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