CREATE TABLE t1(c1 DATETIME NOT NULL PRIMARY KEY, c2 DATETIME NULL, c3 INT, INDEX idx2(c2));
INSERT INTO t1 VALUE('1998-01-01 09:23:45','10-01-01 14:12:33',1);
UPDATE t1 SET c1='2001-01-01' WHERE c2='10-01-01 14:12:33';
SELECT c1,hour(c1),minute(c1),second(c1) FROM t1 WHERE c2='10-01-01 14:12:33';
INSERT INTO t1 VALUES('2009-01-01 08:42:42','2009-01-02 23:59:59',2);
UPDATE t1 SET c1='2009-01-01 1:2:3',c2='2009-01-02 23:59:59.999999' WHERE c2='2009-01-02 23:59:59';
SELECT c1,ADDTIME(c2,'1 1:1:1.000002') FROM t1 WHERE c3=2;
INSERT INTO t1 VALUES('2009-02-25 15:45','09-02-27 15:46',3);
SET TIMESTAMP=1235553613;
UPDATE t1 SET c2=NOW() WHERE c1 >=CURDATE();
UPDATE t1 SET c1=DATE_ADD(CURDATE(),INTERVAL '1 1:1:1' DAY_SECOND) WHERE c2=CURRENT_TIMESTAMP();
--sorted_result
SELECT * FROM t1;
INSERT INTO t1 VALUES('2001-01-06','2001-01-07 09:30:00',4),('2001-01-08',NULL,5);
SELECT * FROM t1 WHERE c2 IS NULL;
UPDATE t1 SET c2=NULL WHERE c1='2001-01-06 00:00:00';
--sorted_result
SELECT * FROM t1 WHERE c2 IS NULL;
DROP TABLE t1;