Function/Procedure都是可独立编译并存储在数据库中的，区别是Function有返回值。
Package则是数据和过程、函数的集合体。
CREATE PROCEDURE dorepeat(p1 INT) BEGIN SET @x = 0; REPEAT SET @x = @x + 1; UNTIL @x > p1 END REPEAT; END;
mysql> delimiter //
mysql> CREATE PROCEDURE dorepeat(p1 INT)
-> BEGIN
-> SET @x = 0;
-> REPEAT SET @x = @x + 1; UNTIL @x > p1 END REPEAT;
-> END
-> //
Query OK, 0 rows affected (0.00 sec)
mysql> delimiter ;
mysql> CALL dorepeat(1000);
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT @x;
+------+
| @x |
+------+
| 1001 |
+------+
1 row in set (0.00 sec)
mysql> CREATE FUNCTION hello (s CHAR(20))
mysql> RETURNS CHAR(50) DETERMINISTIC
-> RETURN CONCAT(‘Hello, ‘,s,‘!‘);
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT hello(‘world‘);
+----------------+
| hello(‘world‘) |
+----------------+
| Hello, world! |
+----------------+
1 row in set (0.00 sec)
【数据库】Function&Procedure&Package
原文：https://www.cnblogs.com/yuelien/p/12375272.html