如何在mysql查询中的2列中拆分10行

Question

在mysql表中有10行，我需要将10行拆分为一列中的5行，再将5列拆分为另一列。

要获得这种结果的查询是什么？

Answer 1

在MySQL中做这件事太可怕了，最好还是用一种应用程序语言来做。

您可以执行以下操作，但是它缺乏任何可扩展性：

0

Answer 2

请尝试下面的查询，它将动态地将行分解为没有任何参数的列，只需将“ Time”替换为您的列名即可。

      SELECT b.*, c.* from 
      (SELECT CEILING(COUNT(id) / 2) as totalId from test) as a JOIN 
      (SELECT id as id1, Time as column1 FROM test) as b LEFT JOIN
      (SELECT id as id2, Time as column2 FROM test) as c
      ON b.id1 = c.id2-a.totalId 
      WHERE b.id1 < a.totalId+1

您也可以将*替换为列名：

      SELECT b.column1, c.column2 from 
      (SELECT CEILING(COUNT(id) / 2) as totalId from test) as a JOIN 
      (SELECT id as id1, Time as column1 FROM test) as b LEFT JOIN
      (SELECT id as id2, Time as column2 FROM test) as c
      ON b.id1 = c.id2-a.totalId 
      WHERE b.id1 < a.totalId+1