從MySql刪除觸發器到Sql Server後翻譯

Question

如何爲MS SQL Server編寫this觸發器？

MySQL版本：

CREATE TRIGGER log_patron_delete AFTER DELETE on patrons 
FOR EACH ROW 
BEGIN 
DELETE FROM patron_info 
    WHERE patron_info.pid = old.id; 
END 

SQL Server版本：

CREATE TRIGGER log_patron_delete ON patrons AFTER DELETE 
AS 
BEGIN 
DELETE FROM patron_info WHERE patron_info.pid = old.id; 
END 

問題：old.id作品MySQL，但是沒有MS SQL Server的

Answer 1

這不是一個爲觸發器工作，這是一個外鍵約束的工作。 您應該在patrons表和patron_info表之間創建一個外鍵，並使用選項delete cascade創建它。

ALTER TABLE patron_info 
ADD CONSTRAINT FK_patron_info_patrons FOREIGN KEY (pid) 
    REFERENCES patrons(id) 
    ON DELETE CASCADE 

這樣，你不能有不相關的惠顧表patron_info任何行，一旦你刪除的惠顧表中patron_info相應的行被自動刪除的行。