DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (a <INT_COLUMN>, b <CHAR_COLUMN>) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
INSERT INTO t1 (a,b) VALUES (1,'a'),(2,'b'),(3,'c'),(4,'d'),(5,'e'),(10000,'foobar');
INSERT INTO t1 (a,b) SELECT a, b FROM t1;
UPDATE t1 SET a=a+100;
SELECT a,b FROM t1;
a	b
101	a
101	a
10100	foobar
10100	foobar
102	b
102	b
103	c
103	c
104	d
104	d
105	e
105	e
UPDATE t1 SET a=a-100, b=DEFAULT WHERE a>100;
SELECT a,b FROM t1;
a	b
1	NULL
1	NULL
10000	NULL
10000	NULL
2	NULL
2	NULL
3	NULL
3	NULL
4	NULL
4	NULL
5	NULL
5	NULL
UPDATE t1 SET b = 'update' WHERE a <= 4 ORDER BY b DESC, a ASC LIMIT 1;
SELECT a,b FROM t1;
a	b
1	NULL
1	update
10000	NULL
10000	NULL
2	NULL
2	NULL
3	NULL
3	NULL
4	NULL
4	NULL
5	NULL
5	NULL
DROP TABLE t1;