整理数据库，需要用mysql实现行转行操作

Question

• 需求：老数据库，需要对其进行数据整理；（行转行）
• 数据库设计：

————**这里的server将近20个，**

类似以上这种设计，把一行数据分解成多行，需要获取的数据是：

该怎么把这一行数据，通过sql拆分成多行呢！

Answer 1

(select id, "server1" as 服务名, server1 as 值 from table)
union (select id, "server2" as 服务名, server2 as 值 from table)
union (select id, "server3" as 服务名, server3 as 值 from table)
union (select id, "server4" as 服务名, server4 as 值 from table)
union (select id, "server5" as 服务名, server5 as 值 from table)