Question

所以我有这个查询

select oldvalue, newvalue from(select 'a' as oldvalue, 'b' as newvalue) as N

现在的问题是，当我想在列中具有多个值时，每列只能有1个值，我曾尝试使用union像这样

select oldvalue, newvalue from(select 'a' as oldvalue, 'b' as newvalue UNION ALL 'c', 'd') as N

现在我有a和c为oldvalue，b和d为newvalue，但是通过并集，我每列只能有2个max值，有没有办法让我在每列中有两个以上的值列

Answer 1

只需用CODE编写@TimBiegeleisen在评论中提到的内容即可。

  SELECT oldvalue, newvalue 
  FROM ( SELECT 'a' as oldvalue, 'b' as newvalue UNION ALL 
       SELECT 'c', 'd' UNION ALL
       SELECT 'e' ,'f' UNION ALL
       SELECT 'g' ,'h' UNION ALL
       SELECT 'i','j' ......
      ) as N

子查询选择多行值

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