mysql存储过程中局部变量定义在代码最前面，作用范围也是在此函数范围内。注意同全局变量和用户变量区分开。

使用 DECLARE 关键字来声明变量

注意必须写在代码块的最前面

 de count int DEFAULT 0;
DECLARE username varchar(32);  

一次声明多个相同类型的变量

 	DECLARE p_parent int DEFAULT 0;
	DECLARE parent0, parent1, parent2, parent3, parent4, parent5 int DEFAULT 0;  

使用set来给变量赋值

set <变量名> = <值>

 				 DECLARE sflag int default 0;
				 set sflag =100;  

select 语句给变量赋值

select 列名 into 变量名，支持多个变量同时赋值。

SELECT col_name[, …] INTO var_name[,…] from table

 SELECT IFNULL(cnt,0) into parent0 from temp_student where b = 0 limit 1;  

 select sname, sno into p_name, p_no from temp_student where id=888;
select 'result:', p_no, p_name;  

游标赋值

 DECLARE p_id int;
DECLARE p_name varchar(32);
DECLARE sflag int DEFAULT 0;
DECLARE cur_school CURSOR FOR select id,name from school where status=0;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET sflag = 1;

open cur_school;		
		fetch cur_school into p_id, p_name;  
		while sflag<>1 do      
       // ......
      fetch cur_school into p_id, p_name;  
      select 'in while:',p_id, sflag;
		end while;
close cur_school;