set @orderNo := 'order3'; 先定义一个@开头的变量值为 order3
SELECT * t_order WHERE order_no = @orderNo; 查询订单号为 order3 的订单
DELETE FROM t_order WHERE order_no = @orderNo; 删除订单号为 order3 的订单
set @orderNo := 'order3'; 先定义一个@开头的变量值为 order3
SELECT * t_order WHERE order_no = @orderNo; 查询订单号为 order3 的订单
DELETE FROM t_order WHERE order_no = @orderNo; 删除订单号为 order3 的订单