SQL SELECT後跟UPDATE

Question

我有Employee表和HR表。員工的地址（地址欄）在兩個表中都有。我想只要有人力資源表的地址和僱員表的地址相同employee.employee-ID之間的不匹配，以更新地址從Employee表，所有這些記錄的HR表的地址欄是員工表和外主鍵在HR表中鍵入。

Answer 1

你仍然可以做JOIN上UPDATE聲明。

UPDATE HR a 
     INNER JOIN Employee b 
      ON a.EmpID = b.ID -- relationship column 
SET  a.address = b.address 
WHERE a.address <> b.address -- to make this query faster 
           -- filter only those address that didn't match