更新和子查詢的問題。 一對多

Question

運行此查詢時，得到表的以下錯誤更新列名稱：

update t1 set t1.DIST_= (SELECT SUM(t2.amount) as DIST_ FROM t2
                         WHERE unique_number =300291 and t2.reseller_id ='31')

我有2個表（t1和t2）t1有DIST_列和unique_number和1行t2有很多行和列的數量，unique_number，reseller_id

此請求必須使用t2.reseller_id = '31'從表t2計算金額，並通過unique_number將值寫入t1.DIST_

現在，請求更改所有表列的值，但是我只需要更新t2.unique_number = t1.unique_number的列

Answer 1

您需要在UPDATE語句中使用WHERE子句：

update t1 set t1.DIST_= (SELECT SUM(t2.amount) as DIST_ FROM t2
                         WHERE unique_number =300291 and t2.reseller_id ='31')
where t1.unique_number = 300291

如果您想更新的所有行t1從相應的總和t2 ，加入一個子查詢組他們。

update t1
JOIN (SELECT unique_number, SUM(amount) AS DIST_
      FROM t2
      WHERE reseller_id = '31'
      GROUP BY unique_number) AS t2
ON t1.unique_number = t2.unique_number
SET t1.DIST_ = t2.DIST_

Answer 2

嘗試像下面使用連接

   UPDATE TABLEA t1 
       JOIN (SELECT unique_number,SUM(t2.amount) as DIST_ FROM table2
            group by unique_number
            ) t2 ON t2.unique_number=t1.unique_number
       SET t1.DIST_ =t2.DIST_