1242 -子查询返回超过1行1

Question

SELECT
dept.deptname,details.UserName,
(select CONCAT(BrndName,' - ',ModName,' - ',Capacity) from details where  Devname='PROCESSOR' ) as Processor,
(select CONCAT(BrndName,' - ',ModName,' - ',Capacity) from details where  Devname='PROCESSOR' ) as Memory
FROM
dept
LEFT JOIN details ON dept.deptcode = details.DeptCode

Answer 1

看起来您试图在子查询中选择3列，然后尝试将它们表示为单个列。

如果我没记错的话，你不能把三列(例如“BrndName”、“Modname”、“Capacity”)合并为一列(例如“crevrtv”)，而不是先将它们连接起来，所以MySQL会将这一事实告知您。

您还试图返回两个别名为'crevrtv‘的列。