MySQL 自定义函数CREATE FUNCTION示例

mysql> mysql> delimiter $$ mysql> mysql> CREATE FUNCTION myFunction -> (in_string VARCHAR(255), -> in_find_str VARCHAR(20), -> in_repl_str VARCHAR(20)) -> -> RETURNS VARCHAR(255) -> BEGIN -> DECLARE l_new_string VARCHAR(255); -> DECLARE l_find_pos INT; -> -> SET l_find_pos=INSTR(in_string,in_find_str); -> -> IF (l_find_pos>0) THEN -> SET l_new_string=INSERT(in_string,l_find_pos,LENGTH(in_find_str),in_repl_str); -> ELSE -> SET l_new_string=in_string; -> END IF; -> RETURN(l_new_string); -> -> END$$ Query OK, 0 rows affected (0.00 sec) mysql> mysql> delimiter ; mysql> select myFunction('ABC','A','Z'); +---------------------------+ | myFunction('ABC','A','Z') | +---------------------------+ | ZBC | +---------------------------+ 1 row in set (0.00 sec) mysql> drop function myFunction; Query OK, 0 rows affected (0.00 sec)