Select fun_variable('rr1','123','5555') ；调用
语句：
CREATE FUNCTION fun_variable()
RETURNS int(20)
BEGIN
DECLARE msg VARCHAR(20);
if not exists (SELECT * FROM class WHERE `name`=name1) then
Insert into class(`name`,`number`) values(name1,number) ;
RETURN msg=1;
else
update class set `number`=newname where `name`=name1;
RETURN msg=0;
end if;
END
