如何使用返回2列的子查询执行IN？

Question

我有这个查询

SELECT *
FROM GUITARS.FENDER
WHERE FENDER.GUITARTYPE IN (
SELECT GUITARTYPE,GUITARSUBTYPE
FROM GUITARS.GUITAR_TYPE
WHERE GuitarColor = 'RED')

当我只在子查询中执行GUITARTYPE而不是GUITARTYPE，GUITARSUBTYPE时，我可以运行它。

Answer 1

请勿使用in，请使用exists：

SELECT *
FROM GUITARS.FENDER
WHERE EXISTS (SELECT 1
              FROM GUITARS.GUITAR_TYPE
              WHERE GuitarColor = 'RED' AND
                    FENDER.GUITARTYPE = GUITARTYPE.GUITARTYPE AND
                    FENDER.GUITARSUBTYPE = GUITARTYPE.GUITARSUBTYPE
             );