mysql——使用——函数——示例

前期数据准备：

create table employee ( num int(50),
                        d_id int(50),
                        name varchar(50),
                        age int(50),
                        sex varchar(50),
                        homeadd varchar(50)
                       );

insert into employee values(1,1001,‘zhangsan‘,26,‘nan‘,‘beijing‘);
insert into employee values(2,1001,‘lisi‘,24,‘nv‘,‘hunan‘);
insert into employee values(3,1002,‘wangwu‘,25,‘nan‘,‘jiangsu‘);
insert into employee values(4,1004,‘aric‘,15,‘nan‘,‘yingguo‘);

select * from employee;

create table department ( d_id int(50),
                          d_name varchar(50),
                          functione varchar(50),
                          address varchar(50)
                        );

insert into department values(1001,‘keyanbu‘,‘yanfachanpin‘,‘3lou5hao‘);
insert into department values(1002,‘shengchanbu‘,‘shengchanchanp‘,‘5louyiceng‘);
insert into department values(1003,‘xiaoshoubu‘,‘cehuaxiaoshou‘,‘1louxiaoshoudating‘);



select * from employee;

select * from department;

 

 

 

定义一个存储函数：

delimiter &&

create function name_from_employee ( emp_id INT )

returns varchar(20)

begin

     return ( select name from employee where num = emp_id );

end &&

delimiter;

 

 

 

 

 

查看此存储函数的状态：

show function status like ‘name_from_employee‘;

 

 

 

 

 

查看此函数的定义：

show create function name_from_employee;

 

 

 

 

调用此函数：

select name_from_employee(3);

 

 

 

 

 

删除此函数：

drop function name_from_employee;