DELETE FROM mysql.user WHERE User LIKE 'mysqltest_%';
DELETE FROM mysql.db WHERE User LIKE 'mysqltest_%';
DELETE FROM mysql.tables_priv WHERE User LIKE 'mysqltest_%';
DELETE FROM mysql.columns_priv WHERE User LIKE 'mysqltest_%';
FLUSH PRIVILEGES;
DROP DATABASE IF EXISTS mysqltest_db1;
CREATE DATABASE mysqltest_db1;
CREATE USER mysqltest_dfn@localhost;
CREATE USER mysqltest_inv@localhost;
GRANT SUPER ON *.* TO mysqltest_dfn@localhost;
GRANT CREATE ON mysqltest_db1.* TO mysqltest_dfn@localhost;

---> connection: wl2818_definer_con
CREATE TABLE t1(num_value INT);
CREATE TABLE t2(user_str TEXT);
CREATE TRIGGER wl2818_trg1 BEFORE INSERT ON t1
FOR EACH ROW
INSERT INTO t2 VALUES(CURRENT_USER());

---> patching t1.TRG...

CREATE TRIGGER wl2818_trg2 AFTER INSERT ON t1
FOR EACH ROW
INSERT INTO t2 VALUES(CURRENT_USER());
Warnings:
Warning	1454	No definer attribute for trigger 'mysqltest_db1'.'wl2818_trg1'. The trigger will be activated under the authorization of the invoker, which may have insufficient privileges. Please recreate the trigger.

SELECT trigger_name, definer FROM INFORMATION_SCHEMA.TRIGGERS ORDER BY trigger_name;
trigger_name	definer
wl2818_trg1	
wl2818_trg2	mysqltest_dfn@localhost
Warnings:
Warning	1454	No definer attribute for trigger 'mysqltest_db1'.'wl2818_trg1'. The trigger will be activated under the authorization of the invoker, which may have insufficient privileges. Please recreate the trigger.

SELECT * FROM INFORMATION_SCHEMA.TRIGGERS ORDER BY trigger_name;
TRIGGER_CATALOG	TRIGGER_SCHEMA	TRIGGER_NAME	EVENT_MANIPULATION	EVENT_OBJECT_CATALOG	EVENT_OBJECT_SCHEMA	EVENT_OBJECT_TABLE	ACTION_ORDER	ACTION_CONDITION	ACTION_STATEMENT	ACTION_ORIENTATION	ACTION_TIMING	ACTION_REFERENCE_OLD_TABLE	ACTION_REFERENCE_NEW_TABLE	ACTION_REFERENCE_OLD_ROW	ACTION_REFERENCE_NEW_ROW	CREATED	SQL_MODE	DEFINER
NULL	mysqltest_db1	wl2818_trg1	INSERT	NULL	mysqltest_db1	t1	0	NULL	INSERT INTO t2 VALUES(CURRENT_USER())	ROW	BEFORE	NULL	NULL	OLD	NEW	NULL		
NULL	mysqltest_db1	wl2818_trg2	INSERT	NULL	mysqltest_db1	t1	0	NULL	INSERT INTO t2 VALUES(CURRENT_USER())	ROW	AFTER	NULL	NULL	OLD	NEW	NULL		mysqltest_dfn@localhost
DROP TRIGGER wl2818_trg1;
Warnings:
Warning	1454	No definer attribute for trigger 'mysqltest_db1'.'wl2818_trg1'. The trigger will be activated under the authorization of the invoker, which may have insufficient privileges. Please recreate the trigger.
DROP TRIGGER wl2818_trg2;
use mysqltest_db1;
DROP TABLE t1;
DROP TABLE t2;
DROP USER mysqltest_dfn@localhost;
DROP USER mysqltest_inv@localhost;
DROP DATABASE mysqltest_db1;