drop database if exists events_test;
drop database if exists db_x;
drop database if exists mysqltest_db2;
drop database if exists mysqltest_no_such_database;
create database events_test;
use events_test;
CREATE USER pauline@localhost;
CREATE DATABASE db_x;
GRANT EVENT ON db_x.* TO pauline@localhost;
USE db_x;
CREATE TABLE x_table(a int);
CREATE EVENT e_x1 ON SCHEDULE EVERY 1 SECOND DO DROP DATABASE db_x;
CREATE EVENT e_x2 ON SCHEDULE EVERY 1 SECOND DO DROP TABLE x_table;
SHOW DATABASES LIKE 'db_x';
Database (db_x)
db_x
SET GLOBAL event_scheduler=1;
SHOW DATABASES LIKE 'db_x';
Database (db_x)
db_x
SHOW TABLES FROM db_x;
Tables_in_db_x
x_table
SET GLOBAL event_scheduler=off;
DROP EVENT e_x1;
DROP EVENT e_x2;
DROP DATABASE db_x;
DROP USER pauline@localhost;
USE events_test;
SET GLOBAL event_scheduler=off;
drop event if exists event1;
Warnings:
Note	1305	Event event1 does not exist
create event event1 on schedule every 15 minute starts now() ends date_add(now(), interval 5 hour) DO begin end;
alter event event1 rename to event2 enable;
alter event event2 disable;
alter event event2 enable;
alter event event2 on completion not preserve;
alter event event2 on schedule every 1 year on completion preserve rename to event3 comment "new comment" do begin select 1; end__
alter event event3 rename to event2;
drop event event2;
create event event2 on schedule every 2 second starts now() ends date_add(now(), interval 5 hour) comment "some" DO begin end;
drop event event2;
CREATE EVENT event_starts_test ON SCHEDULE EVERY 10 SECOND COMMENT "" DO SELECT 1;
SELECT interval_field, interval_value, body FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
interval_field	interval_value	body
SECOND	10	SELECT 1
SELECT execute_at IS NULL, starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
execute_at IS NULL	starts IS NULL	ends IS NULL	comment
1	0	1	
ALTER EVENT event_starts_test ON SCHEDULE AT '2020-02-02 20:00:02';
SELECT execute_at IS NULL, starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
execute_at IS NULL	starts IS NULL	ends IS NULL	comment
0	1	1	
ALTER EVENT event_starts_test COMMENT "non-empty comment";
SELECT execute_at IS NULL, starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
execute_at IS NULL	starts IS NULL	ends IS NULL	comment
0	1	1	non-empty comment
ALTER EVENT event_starts_test COMMENT "";
SELECT execute_at IS NULL, starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
execute_at IS NULL	starts IS NULL	ends IS NULL	comment
0	1	1	
DROP EVENT event_starts_test;
CREATE EVENT event_starts_test ON SCHEDULE EVERY 20 SECOND STARTS '2020-02-02 20:00:02' ENDS '2022-02-02 20:00:02' DO SELECT 2;
SELECT execute_at IS NULL, starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
execute_at IS NULL	starts IS NULL	ends IS NULL	comment
1	0	0	
ALTER EVENT event_starts_test COMMENT "non-empty comment";
SELECT execute_at IS NULL, starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
execute_at IS NULL	starts IS NULL	ends IS NULL	comment
1	0	0	non-empty comment
ALTER EVENT event_starts_test COMMENT "";
SELECT execute_at IS NULL, starts IS NULL, ends IS NULL, comment FROM mysql.event WHERE db='events_test' AND name='event_starts_test';
execute_at IS NULL	starts IS NULL	ends IS NULL	comment
1	0	0	
DROP EVENT event_starts_test;
create table test_nested(a int);
create event e_43 on schedule every 1 second do set @a = 5;
alter event e_43 do alter event e_43 do set @a = 4;
ERROR HY000: Recursion of EVENT DDL statements is forbidden when body is present
alter event e_43 do
begin
alter event e_43 on schedule every 5 minute;
insert into test_nested values(1);
end|
set global event_scheduler = on;
select db, name, body, status, interval_field, interval_value from mysql.event;
db	name	body	status	interval_field	interval_value
events_test	e_43	begin
alter event e_43 on schedule every 5 minute;
insert into test_nested values(1);
end	ENABLED	MINUTE	5
drop event e_43;
drop table test_nested;
"Let's check whether we can use non-qualified names"
create table non_qualif(a int);
create event non_qualif_ev on schedule every 10 minute do insert into non_qualif values (800219);
select * from non_qualif;
a
800219
drop event non_qualif_ev;
drop table non_qualif;
alter event non_existant rename to non_existant_too;
ERROR HY000: Unknown event 'non_existant'
set global event_scheduler = off;
create event existant on schedule at now() + interval 1 year do select 12;
alter event non_existant rename to existant;
ERROR HY000: Event 'existant' already exists
alter event existant rename to events_test.existant;
ERROR HY000: Same old and new event name
drop event existant;
create table t_event3 (a int, b float);
drop event if exists event3;
Warnings:
Note	1305	Event event3 does not exist
create event event3 on schedule every 50 + 10 minute starts date_add("20100101", interval 5 minute) ends date_add("20151010", interval 5 day) comment "portokala_comment" DO insert into t_event3 values (unix_timestamp(), rand());
select count(*) from t_event3;
count(*)
0
drop event event3;
drop table t_event3;
set names utf8;
CREATE EVENT root6 ON SCHEDULE EVERY '10:20' MINUTE_SECOND ON COMPLETION PRESERVE ENABLE COMMENT 'some comment' DO select 1;
SHOW CREATE EVENT root6;
Event	sql_mode	time_zone	Create Event
root6		SYSTEM	CREATE EVENT `root6` ON SCHEDULE EVERY '10:20' MINUTE_SECOND STARTS '#' ON COMPLETION PRESERVE ENABLE COMMENT 'some comment' DO select 1
create event root7 on schedule every 2 year do select 1;
SHOW CREATE EVENT root7;
Event	sql_mode	time_zone	Create Event
root7		SYSTEM	CREATE EVENT `root7` ON SCHEDULE EVERY 2 YEAR STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root8 on schedule every '2:5' year_month do select 1;
SHOW CREATE EVENT root8;
Event	sql_mode	time_zone	Create Event
root8		SYSTEM	CREATE EVENT `root8` ON SCHEDULE EVERY '2-5' YEAR_MONTH STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root8_1 on schedule every '2:15' year_month do select 1;
SHOW CREATE EVENT root8_1;
Event	sql_mode	time_zone	Create Event
root8_1		SYSTEM	CREATE EVENT `root8_1` ON SCHEDULE EVERY '3-3' YEAR_MONTH STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root9 on schedule every 2 week ON COMPLETION PRESERVE DISABLE COMMENT 'коментар на кирилица' do select 1;
SHOW CREATE EVENT root9;
Event	sql_mode	time_zone	Create Event
root9		SYSTEM	CREATE EVENT `root9` ON SCHEDULE EVERY 2 WEEK STARTS '#' ON COMPLETION PRESERVE DISABLE COMMENT 'коментар на кирилица' DO select 1
create event root10 on schedule every '20:5' day_hour do select 1;
SHOW CREATE EVENT root10;
Event	sql_mode	time_zone	Create Event
root10		SYSTEM	CREATE EVENT `root10` ON SCHEDULE EVERY '20 5' DAY_HOUR STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root11 on schedule every '20:25' day_hour do select 1;
SHOW CREATE EVENT root11;
Event	sql_mode	time_zone	Create Event
root11		SYSTEM	CREATE EVENT `root11` ON SCHEDULE EVERY '21 1' DAY_HOUR STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root12 on schedule every '20:25' hour_minute do select 1;
SHOW CREATE EVENT root12;
Event	sql_mode	time_zone	Create Event
root12		SYSTEM	CREATE EVENT `root12` ON SCHEDULE EVERY '20:25' HOUR_MINUTE STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root13 on schedule every '25:25' hour_minute do select 1;
SHOW CREATE EVENT root13;
Event	sql_mode	time_zone	Create Event
root13		SYSTEM	CREATE EVENT `root13` ON SCHEDULE EVERY '25:25' HOUR_MINUTE STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root13_1 on schedule every '11:65' hour_minute do select 1;
SHOW CREATE EVENT root13_1;
Event	sql_mode	time_zone	Create Event
root13_1		SYSTEM	CREATE EVENT `root13_1` ON SCHEDULE EVERY '12:5' HOUR_MINUTE STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root14 on schedule every '35:35' minute_second do select 1;
SHOW CREATE EVENT root14;
Event	sql_mode	time_zone	Create Event
root14		SYSTEM	CREATE EVENT `root14` ON SCHEDULE EVERY '35:35' MINUTE_SECOND STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root15 on schedule every '35:66' minute_second do select 1;
SHOW CREATE EVENT root15;
Event	sql_mode	time_zone	Create Event
root15		SYSTEM	CREATE EVENT `root15` ON SCHEDULE EVERY '36:6' MINUTE_SECOND STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root16 on schedule every '35:56' day_minute do select 1;
SHOW CREATE EVENT root16;
Event	sql_mode	time_zone	Create Event
root16		SYSTEM	CREATE EVENT `root16` ON SCHEDULE EVERY '1 11:56' DAY_MINUTE STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root17 on schedule every '35:12:45' day_minute do select 1;
SHOW CREATE EVENT root17;
Event	sql_mode	time_zone	Create Event
root17		SYSTEM	CREATE EVENT `root17` ON SCHEDULE EVERY '35 12:45' DAY_MINUTE STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root17_1 on schedule every '35:25:65' day_minute do select 1;
SHOW CREATE EVENT root17_1;
Event	sql_mode	time_zone	Create Event
root17_1		SYSTEM	CREATE EVENT `root17_1` ON SCHEDULE EVERY '36 2:5' DAY_MINUTE STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root18 on schedule every '35:12:45' hour_second do select 1;
SHOW CREATE EVENT root18;
Event	sql_mode	time_zone	Create Event
root18		SYSTEM	CREATE EVENT `root18` ON SCHEDULE EVERY '35:12:45' HOUR_SECOND STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root19 on schedule every '15:59:85' hour_second do select 1;
SHOW CREATE EVENT root19;
Event	sql_mode	time_zone	Create Event
root19		SYSTEM	CREATE EVENT `root19` ON SCHEDULE EVERY '16:0:25' HOUR_SECOND STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
create event root20 on schedule every '50:20:12:45' day_second do select 1;
SHOW CREATE EVENT root20;
Event	sql_mode	time_zone	Create Event
root20		SYSTEM	CREATE EVENT `root20` ON SCHEDULE EVERY '50 20:12:45' DAY_SECOND STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
set names cp1251;
create event ����21 on schedule every '50:23:59:95' day_second COMMENT '���� � 1251 ��������' do select 1;
SHOW CREATE EVENT ����21;
Event	sql_mode	time_zone	Create Event
����21		SYSTEM	CREATE EVENT `����21` ON SCHEDULE EVERY '51 0:0:35' DAY_SECOND STARTS '#' ON COMPLETION NOT PRESERVE ENABLE COMMENT '���� � 1251 ��������' DO select 1
insert into mysql.event (db, name, body, definer, interval_value, interval_field) values (database(), "root22", "select 1", user(), 100, "SECOND_MICROSECOND");
show create event root22;
ERROR 42000: This version of MySQL doesn't yet support 'MICROSECOND'
SHOW EVENTS;
ERROR 42000: This version of MySQL doesn't yet support 'MICROSECOND'
drop event root22;
create event root23 on schedule every -100 year do select 1;
ERROR HY000: INTERVAL is either not positive or too big
create event root23 on schedule every 222222222222222222222 year do select 1;
ERROR HY000: INTERVAL is either not positive or too big
drop event root6;
drop event root7;
drop event root8;
drop event root8_1;
drop event root9;
drop event root10;
drop event root11;
drop event root12;
drop event root13;
drop event root13_1;
drop event root14;
drop event root15;
drop event root16;
drop event root17;
drop event root17_1;
drop event root18;
drop event root19;
drop event root20;
drop event ����21;
set names latin1;
Create a test event. Only event metadata is relevant, 
the actual schedule and body are not.
CREATE EVENT intact_check ON SCHEDULE EVERY 10 HOUR DO SELECT "nothing";
SHOW EVENTS;
Db	Name	Definer	Time zone	Type	Execute at	Interval value	Interval field	Starts	Ends	Status
events_test	intact_check	root@localhost	SYSTEM	RECURRING	NULL	10	#	#	NULL	ENABLED
Try to alter mysql.event: the server should fail to load
event information after mysql.event was tampered with.

First, let's add a column to the end and make sure everything
works as before

ALTER TABLE mysql.event ADD dummy INT;
SHOW EVENTS;
Db	Name	Definer	Time zone	Type	Execute at	Interval value	Interval field	Starts	Ends	Status
events_test	intact_check	root@localhost	SYSTEM	RECURRING	NULL	10	#	#	NULL	ENABLED
SELECT event_name FROM INFORMATION_SCHEMA.events;
event_name
intact_check
SHOW CREATE EVENT intact_check;
Event	sql_mode	time_zone	Create Event
intact_check		SYSTEM	CREATE EVENT `intact_check` ON SCHEDULE EVERY 10 HOUR STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO SELECT "nothing"
DROP EVENT no_such_event;
ERROR HY000: Unknown event 'no_such_event'
CREATE EVENT intact_check_1 ON SCHEDULE EVERY 5 HOUR DO SELECT 5;
ALTER EVENT intact_check_1 ON SCHEDULE EVERY 8 HOUR DO SELECT 8;
ALTER EVENT intact_check_1 RENAME TO intact_check_2;
DROP EVENT intact_check_1;
ERROR HY000: Unknown event 'intact_check_1'
DROP EVENT intact_check_2;
DROP EVENT intact_check;
DROP DATABASE IF EXISTS mysqltest_no_such_database;
Warnings:
Note	1008	Can't drop database 'mysqltest_no_such_database'; database doesn't exist
CREATE DATABASE mysqltest_db2;
DROP DATABASE mysqltest_db2;
SELECT @@event_scheduler;
@@event_scheduler
OFF
SHOW VARIABLES LIKE 'event_scheduler';
Variable_name	Value
event_scheduler	OFF
SET GLOBAL event_scheduler=OFF;
ALTER TABLE mysql.event DROP dummy;
CREATE EVENT intact_check ON SCHEDULE EVERY 10 HOUR DO SELECT "nothing";

Now let's add a column to the first position: the server
expects to see event schema name there

ALTER TABLE mysql.event ADD dummy INT FIRST;
SHOW EVENTS;
ERROR HY000: Cannot load from mysql.event. The table is probably corrupted
SELECT event_name FROM INFORMATION_SCHEMA.events;
ERROR HY000: Cannot load from mysql.event. The table is probably corrupted
SHOW CREATE EVENT intact_check;
ERROR HY000: Unknown event 'intact_check'
DROP EVENT no_such_event;
ERROR HY000: Unknown event 'no_such_event'
CREATE EVENT intact_check_1 ON SCHEDULE EVERY 5 HOUR DO SELECT 5;
ERROR HY000: Cannot load from mysql.event. The table is probably corrupted
ALTER EVENT intact_check_1 ON SCHEDULE EVERY 8 HOUR DO SELECT 8;
ERROR HY000: Unknown event 'intact_check_1'
ALTER EVENT intact_check_1 RENAME TO intact_check_2;
ERROR HY000: Unknown event 'intact_check_1'
DROP EVENT intact_check_1;
ERROR HY000: Unknown event 'intact_check_1'
DROP EVENT intact_check_2;
ERROR HY000: Unknown event 'intact_check_2'
DROP EVENT intact_check;
ERROR HY000: Unknown event 'intact_check'
DROP DATABASE IF EXISTS mysqltest_no_such_database;
Warnings:
Note	1008	Can't drop database 'mysqltest_no_such_database'; database doesn't exist
CREATE DATABASE mysqltest_db2;
DROP DATABASE mysqltest_db2;
SELECT @@event_scheduler;
@@event_scheduler
OFF
SHOW VARIABLES LIKE 'event_scheduler';
Variable_name	Value
event_scheduler	OFF
SET GLOBAL event_scheduler=OFF;
Clean up
ALTER TABLE mysql.event DROP dummy;
DELETE FROM mysql.event;
CREATE EVENT intact_check ON SCHEDULE EVERY 10 HOUR DO SELECT "nothing";
Back up the table, further changes are not reversible
CREATE TABLE event_like LIKE mysql.event;
INSERT INTO event_like SELECT * FROM mysql.event;

Drop some columns and try more checks. 


ALTER TABLE mysql.event DROP comment, DROP starts;
SHOW EVENTS;
ERROR HY000: Cannot load from mysql.event. The table is probably corrupted
SELECT event_name FROM INFORMATION_SCHEMA.EVENTS;
ERROR HY000: Cannot load from mysql.event. The table is probably corrupted
SHOW CREATE EVENT intact_check;
ERROR HY000: Cannot load from mysql.event. The table is probably corrupted
DROP EVENT no_such_event;
ERROR HY000: Unknown event 'no_such_event'
CREATE EVENT intact_check_1 ON SCHEDULE EVERY 5 HOUR DO SELECT 5;
ERROR HY000: Column count of mysql.event is wrong. Expected 17, found 15. The table is probably corrupted
ALTER EVENT intact_check_1 ON SCHEDULE EVERY 8 HOUR DO SELECT 8;
ERROR HY000: Unknown event 'intact_check_1'
ALTER EVENT intact_check_1 RENAME TO intact_check_2;
ERROR HY000: Unknown event 'intact_check_1'
DROP EVENT intact_check_1;
ERROR HY000: Unknown event 'intact_check_1'
DROP EVENT intact_check_2;
ERROR HY000: Unknown event 'intact_check_2'
DROP EVENT intact_check;
DROP DATABASE IF EXISTS mysqltest_no_such_database;
Warnings:
Note	1008	Can't drop database 'mysqltest_no_such_database'; database doesn't exist
CREATE DATABASE mysqltest_db2;
DROP DATABASE mysqltest_db2;
SELECT @@event_scheduler;
@@event_scheduler
OFF
SHOW VARIABLES LIKE 'event_scheduler';
Variable_name	Value
event_scheduler	OFF
SET GLOBAL event_scheduler=OFF;

Now drop the table, and test again


DROP TABLE mysql.event;
SHOW EVENTS;
ERROR 42S02: Table 'mysql.event' doesn't exist
SELECT event_name FROM INFORMATION_SCHEMA.events;
ERROR 42S02: Table 'mysql.event' doesn't exist
SHOW CREATE EVENT intact_check;
ERROR 42S02: Table 'mysql.event' doesn't exist
DROP EVENT no_such_event;
ERROR 42S02: Table 'mysql.event' doesn't exist
CREATE EVENT intact_check_1 ON SCHEDULE EVERY 5 HOUR DO SELECT 5;
ERROR 42S02: Table 'mysql.event' doesn't exist
ALTER EVENT intact_check_1 ON SCHEDULE EVERY 8 HOUR DO SELECT 8;
ERROR 42S02: Table 'mysql.event' doesn't exist
ALTER EVENT intact_check_1 RENAME  TO intact_check_2;
ERROR 42S02: Table 'mysql.event' doesn't exist
DROP EVENT intact_check_1;
ERROR 42S02: Table 'mysql.event' doesn't exist
DROP EVENT intact_check_2;
ERROR 42S02: Table 'mysql.event' doesn't exist
DROP EVENT intact_check;
ERROR 42S02: Table 'mysql.event' doesn't exist
DROP DATABASE IF EXISTS mysqltest_no_such_database;
Warnings:
Note	1008	Can't drop database 'mysqltest_no_such_database'; database doesn't exist
Error	1146	Table 'mysql.event' doesn't exist
CREATE DATABASE mysqltest_db2;
DROP DATABASE mysqltest_db2;
OK, there is an unnecessary warning about the non-existent table 
but it's not easy to fix and no one complained about it.
A similar warning is printed if mysql.proc is missing.
SHOW WARNINGS;
Level	Code	Message
Error	1146	Table 'mysql.event' doesn't exist
SELECT @@event_scheduler;
@@event_scheduler
OFF
SHOW VARIABLES LIKE 'event_scheduler';
Variable_name	Value
event_scheduler	OFF
SET GLOBAL event_scheduler=OFF;
Restore the original table.
CREATE TABLE mysql.event like event_like;
DROP TABLE event_like;
SHOW EVENTS;
Db	Name	Definer	Time zone	Type	Execute at	Interval value	Interval field	Starts	Ends	Status
create event e_26 on schedule at '2017-01-01 00:00:00' disable do set @a = 5;
select db, name, body, definer, convert_tz(execute_at, 'UTC', 'SYSTEM'), on_completion from mysql.event;
db	name	body	definer	convert_tz(execute_at, 'UTC', 'SYSTEM')	on_completion
events_test	e_26	set @a = 5	root@localhost	2017-01-01 00:00:00	DROP
drop event e_26;
create event e_26 on schedule at NULL disable do set @a = 5;
ERROR HY000: Incorrect AT value: 'NULL'
create event e_26 on schedule at 'definitely not a datetime' disable do set @a = 5;
ERROR HY000: Incorrect AT value: 'definitely not a datetime'
set names utf8;
create event задачка on schedule every 123 minute starts now() ends now() + interval 1 month do select 1;
drop event задачка;
set event_scheduler=off;
ERROR HY000: Variable 'event_scheduler' is a GLOBAL variable and should be set with SET GLOBAL
set global event_scheduler=3;
ERROR 42000: Variable 'event_scheduler' can't be set to the value of '3'
set global event_scheduler=disabled;
ERROR 42000: Variable 'event_scheduler' can't be set to the value of 'disabled'
"DISABLE the scheduler. Testing that it does not work when the variable is 0"
set global event_scheduler=off;
select definer, name, db from mysql.event;
definer	name	db
select get_lock("test_lock1", 20);
get_lock("test_lock1", 20)
1
create event закачка on schedule every 10 hour do select get_lock("test_lock1", 20);
"Should return 1 row"
select definer, name, db from mysql.event;
definer	name	db
root@localhost	закачка	events_test
"Should be only 1 process"
select /*1*/ user, host, db, command, state, info from information_schema.processlist where (command!='Daemon' || user='event_scheduler') and (info is null or info not like '%processlist%') order by info;
user	host	db	command	state	info
select release_lock("test_lock1");
release_lock("test_lock1")
1
drop event закачка;
"Should have 0 events"
select count(*) from mysql.event;
count(*)
0
"ENABLE the scheduler and get a lock"
set global event_scheduler=on;
select get_lock("test_lock2", 20);
get_lock("test_lock2", 20)
1
"Create an event which tries to acquire a mutex. The event locks on the mutex"
create event закачка on schedule every 10 hour do select get_lock("test_lock2", 20);
"Let some time pass to the event starts"
"Should have only 2 processes: the scheduler and the locked event"
select /*2*/ user, host, db, command, state, info from information_schema.processlist where (command!='Daemon' || user='event_scheduler') and (info is null or info not like '%processlist%') order by info;
user	host	db	command	state	info
event_scheduler	localhost	NULL	Daemon	Waiting for next activation	NULL
root	localhost	events_test	Connect	User lock	select get_lock("test_lock2", 20)
"Release the mutex, the event worker should finish."
"Release the mutex, the event worker should finish."
select release_lock("test_lock2");
release_lock("test_lock2")
1
drop event закачка;
set global event_scheduler=1;
select get_lock("test_lock2_1", 20);
get_lock("test_lock2_1", 20)
1
create event закачка21 on schedule every 10 hour do select get_lock("test_lock2_1", 20);
"Should have only 3 processes: the scheduler, our conn and the locked event"
select /*3*/ user, host, db, command, state, info from information_schema.processlist where (command!='Daemon' || user='event_scheduler') and (info is null or info not like '%processlist%') order by info;
user	host	db	command	state	info
event_scheduler	localhost	NULL	Daemon	Waiting for next activation	NULL
root	localhost	events_test	Connect	User lock	select get_lock("test_lock2_1", 20)
set global event_scheduler=off;
"Should have only our process now:"
select /*4*/ user, host, db, command, state, info from information_schema.processlist where (command!='Daemon' || user='event_scheduler') and (info is null or info not like '%processlist%') order by info;
user	host	db	command	state	info
root	localhost	events_test	Connect	User lock	select get_lock("test_lock2_1", 20)
drop event закачка21;
create table t_16 (s1 int);
create trigger t_16_bi before insert on t_16 for each row create event  e_16 on schedule every 1 second do set @a=5;
ERROR HY000: Recursion of EVENT DDL statements is forbidden when body is present
drop table t_16;
create event white_space
on schedule every 10 hour
disable
do
select 1;
select event_schema, event_name, definer, event_definition from information_schema.events where event_name='white_space';
event_schema	event_name	definer	event_definition
events_test	white_space	root@localhost	select 1
drop event white_space;
create event white_space on schedule every 10 hour disable do
select 2;
select event_schema, event_name, definer, event_definition from information_schema.events where event_name='white_space';
event_schema	event_name	definer	event_definition
events_test	white_space	root@localhost	select 2
drop event white_space;
create event white_space on schedule every 10 hour disable do	select 3;
select event_schema, event_name, definer, event_definition from information_schema.events where event_name='white_space';
event_schema	event_name	definer	event_definition
events_test	white_space	root@localhost	select 3
drop event white_space;
create event e1 on schedule every 1 year do set @a = 5;
create table t1 (s1 int);
create trigger t1_ai after insert on t1 for each row show create event e1;
ERROR 0A000: Not allowed to return a result set from a trigger
drop table t1;
drop event e1;
SHOW EVENTS FROM aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa;
ERROR 42000: Incorrect database name 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'
SHOW EVENTS FROM ``;
ERROR 42000: Incorrect database name ''
SHOW EVENTS FROM `events\\test`;
Db	Name	Definer	Time zone	Type	Execute at	Interval value	Interval field	Starts	Ends	Status

LOCK TABLES mode.

create table t1 (a int);
create event e1 on schedule every 10 hour do select 1;
lock table t1 read;
show create event e1;
Event	sql_mode	time_zone	Create Event
e1		SYSTEM	CREATE EVENT `e1` ON SCHEDULE EVERY 10 HOUR STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
select event_name from information_schema.events;
event_name
e1
create event e2 on schedule every 10 hour do select 1;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
alter event e2 disable;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
alter event e2 rename to e3;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
drop event e2;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
drop event e1;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
unlock tables;
lock table t1 write;
show create event e1;
Event	sql_mode	time_zone	Create Event
e1		SYSTEM	CREATE EVENT `e1` ON SCHEDULE EVERY 10 HOUR STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
select event_name from information_schema.events;
event_name
e1
create event e2 on schedule every 10 hour do select 1;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
alter event e2 disable;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
alter event e2 rename to e3;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
drop event e2;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
drop event e1;
ERROR HY000: Table 'event' was not locked with LOCK TABLES
unlock tables;
lock table t1 read, mysql.event read;
show create event e1;
Event	sql_mode	time_zone	Create Event
e1		SYSTEM	CREATE EVENT `e1` ON SCHEDULE EVERY 10 HOUR STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
select event_name from information_schema.events;
event_name
e1
create event e2 on schedule every 10 hour do select 1;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
alter event e2 disable;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
alter event e2 rename to e3;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
drop event e2;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
drop event e1;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
unlock tables;
lock table t1 write, mysql.event read;
show create event e1;
Event	sql_mode	time_zone	Create Event
e1		SYSTEM	CREATE EVENT `e1` ON SCHEDULE EVERY 10 HOUR STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
select event_name from information_schema.events;
event_name
e1
create event e2 on schedule every 10 hour do select 1;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
alter event e2 disable;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
alter event e2 rename to e3;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
drop event e2;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
drop event e1;
ERROR HY000: Table 'event' was locked with a READ lock and can't be updated
unlock tables;
lock table t1 read, mysql.event write;
ERROR HY000: You can't combine write-locking of system tables with other tables or lock types
lock table t1 write, mysql.event write;
ERROR HY000: You can't combine write-locking of system tables with other tables or lock types
lock table mysql.event write;
show create event e1;
Event	sql_mode	time_zone	Create Event
e1		SYSTEM	CREATE EVENT `e1` ON SCHEDULE EVERY 10 HOUR STARTS '#' ON COMPLETION NOT PRESERVE ENABLE DO select 1
select event_name from information_schema.events;
event_name
e1
create event e2 on schedule every 10 hour do select 1;
alter event e2 disable;
alter event e2 rename to e3;
drop event e3;
drop event e1;
unlock tables;
Make sure we have left no events 
select event_name from information_schema.events;
event_name

Events in sub-statements, events and prelocking


create event e1 on schedule every 10 hour do select 1;
create function f1() returns int
begin
show create event e1;
return 1;
end|
ERROR 0A000: Not allowed to return a result set from a function
create trigger trg before insert on t1 for each row
begin
show create event e1;
end|
ERROR 0A000: Not allowed to return a result set from a trigger
create function f1() returns int
begin
select event_name from information_schema.events;
return 1;
end|
ERROR 0A000: Not allowed to return a result set from a function
create trigger trg before insert on t1 for each row
begin
select event_name from information_schema.events;
end|
ERROR 0A000: Not allowed to return a result set from a trigger
create function f1() returns int
begin
create event e2 on schedule every 10 hour do select 1;
return 1;
end|
ERROR HY000: Recursion of EVENT DDL statements is forbidden when body is present
create function f1() returns int
begin
alter event e1 rename to e2;
return 1;
end|
ERROR HY000: Explicit or implicit commit is not allowed in stored function or trigger.
create function f1() returns int
begin
drop event e2;
return 1;
end|
ERROR HY000: Explicit or implicit commit is not allowed in stored function or trigger.
----------------------------------------------------------------------
create trigger trg before insert on t1 for each row
begin
set new.a= f1();
end|
create function f1() returns int
begin
call p1();
return 0;
end|
create procedure p1()
begin
select event_name from information_schema.events;
end|
insert into t1 (a) values (1)|
ERROR 0A000: Not allowed to return a result set from a trigger
drop procedure p1|
create procedure p1()
begin
show create event e1; 
end|
insert into t1 (a) values (1)|
ERROR 0A000: Not allowed to return a result set from a trigger
drop procedure p1|
create procedure p1()
begin
create temporary table tmp select event_name from information_schema.events;
end|
expected to work, since we redirect the output into a tmp table
insert into t1 (a) values (1)|
select * from tmp|
event_name
e1
drop temporary table tmp|
drop procedure p1|
create procedure p1()
begin
alter event e1 rename to e2;
end|
insert into t1 (a) values (1)|
ERROR HY000: Explicit or implicit commit is not allowed in stored function or trigger.
drop procedure p1|
create procedure p1()
begin
drop event e1;
end|
insert into t1 (a) values (1)|
ERROR HY000: Explicit or implicit commit is not allowed in stored function or trigger.
drop table t1|
drop event e1|
drop database events_test;