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; 
