使用存储过程返回多个值
 
可以使用OUT、INOUT参数类型让存储过程返回多个结果值,存储函数不能胜任,因为只能返回一个值。比如统计student数据表里男生和女生人数并通过它的参数返回这两个计数值,让调用者可以访问它们:
 
[sql] 
delimiter $$  
create procedure count_students_by_sex(out p_male int ,out p_female int)  
begin  
select  count(*) from student where sex= 'M' into p_male;  
select count(*) from student where sex='F' into p_feamle;  
end $$  
delimiter ;  

在调用这个过程的时候,把参数替换为用户自定义变量。如:
[sql] 
CALL count_students_by_sex(@mcount,@fcount);  
select 'Number of male students:',@mcount;  

结果:

Number of male studens: @mcount
Number of students: 16