本文介绍了使用MySQL触发器更新客户余额的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
在了解触发器及其工作原理时,我需要一些帮助.我有3张桌子:
I need some help in understanding triggers and how they work. I have 3 tables:
发票
ID |监护人|金额
Invoices
Id | Custid | Amount
付款
ID |客户编号|金额
Payments
Id | CustId | Amount
我有一个插入语句来插入发票:
I have an insert statement to insert the invoices:
$this->db->insert('invoices', array(
'CustomerId' => $data['customerId'],
'Description' => $data['Description'],
'DateCreated' => $data['DateCreated'],
'Amount' => $data['Amount']
));
,并且需要在插入后更新客户余额.同样,在插入或创建付款后.我需要从客户余额中扣除.
and need to update the customers balance after the insert. Similarly, after inserting or creating a payment. I need to deduct from the clients balance.
public function createPayment($data) {
$this->db->insert('payments', array(
'CustomerId' => $data['customerid'],
'DateCreated' => date("Y-m-d H:i:s"),
'Amount' => $data['amount']
));
}
在创建这些触发器时将提供任何帮助.
Any assistance would be appreciated in creating these triggers.
推荐答案
您将需要两个触发器-一个用于发票表:
You'll need two triggers - one for the invoice table:
delimiter //
CREATE TRIGGER add_invoice_to_balance AFTER INSERT ON invoices
FOR EACH
ROW
BEGIN
UPDATE Customers SET balance = balance + NEW.Amount
WHERE Customers.id = NEW.custid;
END;
//
delimiter;
还有一个支付表:
delimiter //
CREATE TRIGGER add_payment_to_balance AFTER INSERT ON payments
FOR EACH
ROW
BEGIN
UPDATE Customers SET balance = balance - NEW.Amount
WHERE Customers.id = NEW.custid;
END;
//
delimiter ;
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