SQLite。在第一個例子中停止滿足WHERE條件

Question

我已經試過這段代碼，它的工作原理，但只對每個客戶的第一個實例。即列應貫穿並將所有訂單添加到以前的欠款中。

UPDATE customers_tbl 
    SET customer_amountowing = customer_amountowing + 
     (SELECT sorder_amount FROM standingorder_tbl 
      WHERE standingorder_tbl.sorder_customer = customers_tbl.customer_address1) 
    WHERE EXISTS 
     (SELECT * FROM standingorder_tbl 
      WHERE standingorder_tbl.sorder_customer = customers_tbl.customer_address1); 

有誰能告訴我因爲我在這裏錯了。乾杯傢伙！

Answer 1

如果您要添加的所有以前的訂單總和的產品，則應使用SUM函數在子查詢以下列方式：

UPDATE customers_tbl 
    SET customer_amountowing = customer_amountowing + 
     (SELECT SUM(sorder_amount) FROM standingorder_tbl 
      WHERE standingorder_tbl.sorder_customer = customers_tbl.customer_address1) 
    WHERE EXISTS 
     (SELECT * FROM standingorder_tbl 
      WHERE standingorder_tbl.sorder_customer = customers_tbl.customer_address1);