1242 - 子查詢返回多於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

看起來您試圖在子查詢中選擇3列 - 然後嘗試將它們表示爲單列。

如果我記得沒錯，你不能將三列（例如'BrndName，Modname，Capacity'）放入一列（例如'crevrtv'）而不先連接它們，所以MySQL會通知你這一事實。

你也試圖用別名'crevrtv'返回兩列。