MYSQL:左连接并使用 group_concat 将外观限制为一个

Question

我有一个这样的sql:

SELECT TASKID, TSK_STATUSID, TSK_CODE, TSK_TITLE, TSK_REF_NO, TSK_DESCRIPTION, STS_NAME, COALESCE(USR_NAME, 'None') AS TUSERNAME 
FROM T_TASK_REQUEST 
LEFT JOIN T_STATUS ON T_STATUS.STATUSID=T_TASK_REQUEST.TSK_STATUSID 
LEFT JOIN T_TASK_USER ON TUS_TASKID = TASKID 
LEFT JOIN T_USER ON USERID = TUS_USERID 
LEFT JOIN T_PROJECT ON T_PROJECT.PROJECTID=T_TASK_REQUEST.PROJECTID 
WHERE TSK_STATUSID='1' AND T_TASK_REQUEST.PROJECTID='2' ORDER BY TASKID DESC LIMIT 10   

当前结果是这样的

如何将 TASKID 分组连接到 1 行，TUSERNAME 结果为:boon|danny|jack|goh|ncc

用|分隔？

在此处查看完整尺寸的 IMG:http://i.stack.imgur.com/WXH3g.jpg

Answer 1

修改后确切的工作SQL是:

SELECT TASKID, TSK_STATUSID, TSK_CODE, TSK_TITLE, TSK_REF_NO, TSK_DESCRIPTION, STS_NAME, GROUP_CONCAT(DISTINCT COALESCE(USR_NAME, 'None') SEPARATOR '|') AS TUSERNAME 
FROM T_TASK_REQUEST 
LEFT JOIN T_STATUS ON T_STATUS.STATUSID=T_TASK_REQUEST.TSK_STATUSID 
LEFT JOIN T_TASK_USER ON TUS_TASKID = TASKID 
LEFT JOIN T_USER ON USERID = TUS_USERID 
LEFT JOIN T_PROJECT ON T_PROJECT.PROJECTID=T_TASK_REQUEST.PROJECTID 
WHERE TSK_STATUSID='1' AND T_TASK_REQUEST.PROJECTID='2' 
GROUP BY TASKID
ORDER BY TASKID DESC LIMIT 10   

感谢@John Woo