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;
BEGIN;
UPDATE t1 SET a=a+100;
UPDATE t1 SET a=a-50, b=DEFAULT WHERE a>100;
COMMIT;
SELECT a,b FROM t1;
a	b
10050	NULL
10050	NULL
51	NULL
51	NULL
52	NULL
52	NULL
53	NULL
53	NULL
54	NULL
54	NULL
55	NULL
55	NULL
BEGIN;
UPDATE t1 SET b = 'update' WHERE a <= 4 ORDER BY a DESC, b ASC LIMIT 3;
UPDATE t1 SET b = '';
ROLLBACK;
BEGIN;
UPDATE t1 SET b = 'update2' WHERE a <= 100;
SAVEPOINT spt1;
UPDATE t1 SET b = '';
ROLLBACK TO SAVEPOINT spt1;
UPDATE t1 SET b = 'upd' WHERE a = 10050;
COMMIT;
SELECT a,b FROM t1;
a	b
10050	upd
10050	upd
51	update2
51	update2
52	update2
52	update2
53	update2
53	update2
54	update2
54	update2
55	update2
55	update2
DROP TABLE t1;