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;