接外贸订单的平台_昌大建设地址_关键词优化的策略有哪些_关键词怎么提取

创建表并导入数据；

mysql> use mydb16_trigger;
Database changed
mysql> create table goods(-> gid char(8) primary key,-> name varchar(10),-> price decimal(8,2),-> num int-> );
Query OK, 0 rows affected (0.07 sec)mysql> create table orders(-> oid int primary key auto_increment,-> gid char(10) not null,-> name varchar(10),-> price decimal(8,2),-> onum int,-> otime date-> );
Query OK, 0 rows affected (0.02 sec)mysql> insert into goods values('A0001','橡皮',2.5,100),('B0001','小楷本',2.8,210),('C0001', '铅笔',1.2,120),('D0001','计算器',28,20);
Query OK, 4 rows affected (0.01 sec)
Records: 4  Duplicates: 0  Warnings: 0

创建触发器：订单表中增加订单数量时，商品表商品数量同步减少对应的商品订单数量；

mysql> delimiter //
mysql> create trigger before_order_insert-> before insert on orders-> for each row-> begin->      update goods->      set num =num - new.onum->      where gid = new.gid;-> end //
Query OK, 0 rows affected (0.05 sec)mysql> delimiter ;
mysql> insert into orders (gid, name, price, onum, otime) values ('A0001', '橡皮', 2.5, 10, '2025-02-09');
Query OK, 0 rows affected (0.04 sec)

 创建触发器：客户取消订单，恢复商品对应商品的数量;

mysql> delimiter //
mysql> create trigger after_order_delete-> after delete on orders-> for each row-> begin->     update goods->     set num = num + old.onum->     where gid = old.gid;-> end //
Query OK, 0 rows affected (0.04 sec)mysql> delimiter ;
mysql> delete from orders where oid = 1;
Query OK, 0 rows affected (0.04 sec)

 创建触发器：客户修改订单，商品对应商品数量同步更新;

mysql> delimiter //
mysql> create trigger after_order_update-> after update on orders-> for each row-> begin->     update goods->     set num = num - new.onum + old.onum->     where gid = new.gid;-> end //
Query OK, 0 rows affected (0.04 sec)mysql> delimiter ;
mysql> update orders set onum = 5 where oid = 1;
Query OK, 0 rows affected (0.00 sec)
Rows matched: 0  Changed: 0  Warnings: 0

创建提取emp_new表所有员工姓名和工资的存储过程s1

mysql> use mydb7_openlab;
Database changed
mysql> delimiter //
mysql> create procedure s1()-> begin->     select 员工姓名, 工资->     from emp_new;-> end //
Query OK, 0 rows affected (0.04 sec)

创建存储过程s2，实现输入员工姓名后返回员工的年龄

mysql> delimiter //
mysql> create procedure s2(in emp_name varchar(50), out emp_age int)-> begin->     select 年龄 into emp_age->     from emp_new->     where 员工姓名 = emp_name;-> end //
Query OK, 0 rows affected (0.04 sec)

创建一个存储过程s3，有2个参数，传入部门号，返回该部门的平均工资

mysql> delimiter //
mysql> create procedure s3(in dept_no int, out avg_salary decimal(10,2))-> begin->     select avg(工资) into avg_salary->     from emp_new->     where 部门号 = dept_no;-> end //
Query OK, 0 rows affected (0.04 sec)