如何正确选择子查询

Question

我有两个查询返回一个条目。我怎样才能 select 这两个 table?

查询 1：Select max([column3]) from [table1] => 42 查询 2：Select Top 1 [column1] from [table1] => 'test'

我想要这样的结果集

result1	result2
42	'test'

但是如何正确地做呢？我可以不知何故 select 吗？

Answer 1

您可以使用 ROW_NUMBER，两次：

WITH cte AS (
    SELECT *, ROW_NUMBER() OVER (ORDER BY column3 DESC) rn1,
              ROW_NUMBER() OVER (ORDER BY some_col) rn2
    FROM table1
)

SELECT MAX(CASE WHEN rn1 = 1 THEN column3 END) AS result1,
       MAX(CASE WHEN rn2 = 1 THEN column1 END) AS result2
FROM cte;

请注意，我假设存在一列 some_col，您打算将其用于选择 column1 值。

如何正确选择子查询

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