Mysql储存过程2:变量定义与参数传递

#储存过程 中的变量定义
declare 变量名 类型 可选类型 -- 跟建表差不多

create procedure p()
begin
declare age int default(18);
declare number int default 1;
select age+number;
end$
/*
mysql> create procedure p()
->   begin
->     declare age int default(18);
->     declare number int default 1;
->     select age+number;
->   end$
Query OK, 0 rows affected (0.00 sec)

mysql> call p$
+------------+
| age+number |
+------------+
|         19 |
+------------+
1 row in set (0.00 sec)

Query OK, 0 rows affected (0.01 sec)
*/
#储存过程 中， 变量可以运算
#运算结果赋修值给变量用: set age := 运算式
#set age := age + 2

#参数传递

mysql> create procedure p2(number int, age int)
->       begin
->         select age+number;
->       end$
Query OK, 0 rows affected (0.00 sec)

mysql> call p2(1,2)$
+------------+
| age+number |
+------------+
|          3 |
+------------+
1 row in set (0.00 sec)

Query OK, 0 rows affected (0.01 sec)

mysql>