SET timestamp=UNIX_TIMESTAMP('2014-09-30 08:00:00');
CREATE FUNCTION f1(str char(20))
RETURNS CHAR(100)
RETURN CONCAT('Hello, ', str, '!');
SELECT * FROM mysql.proc WHERE name like 'f1';
db	name	type	specific_name	language	sql_data_access	is_deterministic	security_type	param_list	returns	body	definer	created	modified	sql_mode	comment	character_set_client	collation_connection	db_collation	body_utf8	aggregate
test	f1	FUNCTION	f1	SQL	CONTAINS_SQL	NO	DEFINER	str char(20)	char(100) CHARSET latin1	RETURN CONCAT('Hello, ', str, '!')	root@localhost	2014-09-30 08:00:00	2014-09-30 08:00:00	STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION		latin1	latin1_swedish_ci	latin1_swedish_ci	RETURN CONCAT('Hello, ', str, '!')	NONE
SELECT f1('world');
f1('world')
Hello, world!
CREATE FUNCTION f1(str char(20))
RETURNS TEXT
RETURN CONCAT('Hello2, ', str, '!');
ERROR 42000: FUNCTION f1 already exists
SELECT body FROM mysql.proc WHERE name like 'f1';
body
RETURN CONCAT('Hello, ', str, '!')
CREATE FUNCTION IF NOT EXISTS f1(str char(20))
RETURNS CHAR(100)
RETURN CONCAT('Hello3, ', str, '!');
Warnings:
Note	1304	FUNCTION f1 already exists
SELECT body FROM mysql.proc WHERE name like 'f1';
body
RETURN CONCAT('Hello, ', str, '!')
CREATE OR REPLACE FUNCTION IF NOT EXISTS f1(str char(20))
RETURNS CHAR(100)
RETURN CONCAT('Hello4, ', str, '!');
ERROR HY000: Incorrect usage of OR REPLACE and IF NOT EXISTS
SELECT body FROM mysql.proc WHERE name like 'f1';
body
RETURN CONCAT('Hello, ', str, '!')
CREATE OR REPLACE FUNCTION f1(str char(20))
RETURNS CHAR(100)
RETURN CONCAT('Hello5, ', str, '!');
SELECT body FROM mysql.proc WHERE name like 'f1';
body
RETURN CONCAT('Hello5, ', str, '!')
DROP FUNCTION f1;
CREATE FUNCTION IF NOT EXISTS f1(str char(20))
RETURNS CHAR(100)
RETURN CONCAT('Hello6, ', str, '!');
SELECT body FROM mysql.proc WHERE name like 'f1';
body
RETURN CONCAT('Hello6, ', str, '!')
SELECT f1('world');
f1('world')
Hello6, world!
DROP FUNCTION IF EXISTS f1;
SELECT body FROM mysql.proc WHERE name like 'f1';
body
DROP FUNCTION IF EXISTS f1;
Warnings:
Note	1305	FUNCTION test.f1 does not exist