如何在更新之前执行MYSQL TRIGGER删除条目

Question

我有两个表，主表是“Invoice”，子表是“Invoice_split”。 在更新“发票”表之前，我想删除子表“Invoice_split”上的相关数据，因为我已经写了下面的查询但是它没有用。

"DELIMITER $$
CREATE TRIGGER before_invoice_update 
BEFORE UPDATE ON mac_invoice FOR EACH ROW 
BEGIN
DELETE FROM mac_invoice_split WHERE OLD.invoice_id = id;
END$$
DELIMITER ;"

id => "Invoice" table primary key
invoice_id =>foreign key of "Invoice" in "Invoice_split" table

Answer 1

你应该试试这个

  WHERE OLD.id = invoice_id;