MySql：从同一个表的三个不同列中提取不同的条目

我有一个名为

deals

的表，它存储

client\u id1

，

client\u id2

，

client\u id3

这些id对应于具有

clientName

和

client\u id

字段的

clients

表

如何创建名称的字符串数组，其ID位于表deals的三列中的任意一列中

SELECT GROUP_CONCAT(Client) FROM (
 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id1 = clients.client_id
UNION ALL
 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id2 = clients.client_id
UNION ALL
 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id3 = clients.client_id)
GROUP BY Client

说明： 从一个表中获取客户端： 工会也会从其他桌子上拿到它们 现在，要获得逗号分隔的字符串，请执行此客户端（php）或让MySQL服务器执行此操作，使用： 说明： 从一个表中获取客户端： 工会也会从其他桌子上拿到它们 现在，要获得逗号分隔的字符串，请执行此客户端（php）或让MySQL服务器执行此操作，使用：

---

你可能应该考虑规范化你的数据，但是你应该考虑规范化你的数据。

 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id1 = clients.client_id

 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id1 = clients.client_id
UNION ALL
 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id2 = clients.client_id
UNION ALL
 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id3 = clients.client_id)

SELECT GROUP_CONCAT(Client) FROM (
 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id1 = clients.client_id
UNION ALL
 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id2 = clients.client_id
UNION ALL
 SELECT clientName as Client 
 FROM deals JOIN clients
 ON deals.client_id3 = clients.client_id)
GROUP BY Client