drop table if exists t1,t2,t3;
select from_days(to_days("960101")),to_days(960201)-to_days("19960101"),to_days(date_add(curdate(), interval 1 day))-to_days(curdate()),weekday("1997-11-29");
from_days(to_days("960101"))	to_days(960201)-to_days("19960101")	to_days(date_add(curdate(), interval 1 day))-to_days(curdate())	weekday("1997-11-29")
1996-01-01	31	1	5
select period_add("9602",-12),period_diff(199505,"9404") ;
period_add("9602",-12)	period_diff(199505,"9404")
199502	13
select now()-now(),weekday(curdate())-weekday(now()),unix_timestamp()-unix_timestamp(now());
now()-now()	weekday(curdate())-weekday(now())	unix_timestamp()-unix_timestamp(now())
0	0	0
select from_unixtime(unix_timestamp("1994-03-02 10:11:12")),from_unixtime(unix_timestamp("1994-03-02 10:11:12"),"%Y-%m-%d %h:%i:%s"),from_unixtime(unix_timestamp("1994-03-02 10:11:12"))+0;
from_unixtime(unix_timestamp("1994-03-02 10:11:12"))	from_unixtime(unix_timestamp("1994-03-02 10:11:12"),"%Y-%m-%d %h:%i:%s")	from_unixtime(unix_timestamp("1994-03-02 10:11:12"))+0
1994-03-02 10:11:12	1994-03-02 10:11:12	19940302101112
select sec_to_time(9001),sec_to_time(9001)+0,time_to_sec("15:12:22"),
sec_to_time(time_to_sec("0:30:47")/6.21);
sec_to_time(9001)	sec_to_time(9001)+0	time_to_sec("15:12:22")	sec_to_time(time_to_sec("0:30:47")/6.21)
02:30:01	23001	54742	00:04:57
select sec_to_time(time_to_sec('-838:59:59'));
sec_to_time(time_to_sec('-838:59:59'))
-838:59:59
select now()-curdate()*1000000-curtime();
now()-curdate()*1000000-curtime()
0
select strcmp(current_timestamp(),concat(current_date()," ",current_time()));
strcmp(current_timestamp(),concat(current_date()," ",current_time()))
0
select strcmp(localtime(),concat(current_date()," ",current_time()));
strcmp(localtime(),concat(current_date()," ",current_time()))
0
select strcmp(localtimestamp(),concat(current_date()," ",current_time()));
strcmp(localtimestamp(),concat(current_date()," ",current_time()))
0
select date_format("1997-01-02 03:04:05", "%M %W %D %Y %y %m %d %h %i %s %w");
date_format("1997-01-02 03:04:05", "%M %W %D %Y %y %m %d %h %i %s %w")
January Thursday 2nd 1997 97 01 02 03 04 05 4
select date_format("1997-01-02", concat("%M %W %D ","%Y %y %m %d %h %i %s %w"));
date_format("1997-01-02", concat("%M %W %D ","%Y %y %m %d %h %i %s %w"))
January Thursday 2nd 1997 97 01 02 12 00 00 4
select dayofmonth("1997-01-02"),dayofmonth(19970323);
dayofmonth("1997-01-02")	dayofmonth(19970323)
2	23
select month("1997-01-02"),year("98-02-03"),dayofyear("1997-12-31");
month("1997-01-02")	year("98-02-03")	dayofyear("1997-12-31")
1	1998	365
select month("2001-02-00"),year("2001-00-00");
month("2001-02-00")	year("2001-00-00")
2	2001
select DAYOFYEAR("1997-03-03"), WEEK("1998-03-03"), QUARTER(980303);
DAYOFYEAR("1997-03-03")	WEEK("1998-03-03")	QUARTER(980303)
62	9	1
select HOUR("1997-03-03 23:03:22"), MINUTE("23:03:22"), SECOND(230322);
HOUR("1997-03-03 23:03:22")	MINUTE("23:03:22")	SECOND(230322)
23	3	22
select week(19980101),week(19970101),week(19980101,1),week(19970101,1);
week(19980101)	week(19970101)	week(19980101,1)	week(19970101,1)
0	0	1	1
select week(19981231),week(19971231),week(19981231,1),week(19971231,1);
week(19981231)	week(19971231)	week(19981231,1)	week(19971231,1)
52	52	53	53
select week(19950101),week(19950101,1);
week(19950101)	week(19950101,1)
1	0
select yearweek('1981-12-31',1),yearweek('1982-01-01',1),yearweek('1982-12-31',1),yearweek('1983-01-01',1);
yearweek('1981-12-31',1)	yearweek('1982-01-01',1)	yearweek('1982-12-31',1)	yearweek('1983-01-01',1)
198153	198153	198252	198252
select yearweek('1987-01-01',1),yearweek('1987-01-01');
yearweek('1987-01-01',1)	yearweek('1987-01-01')
198701	198652
select week("2000-01-01",0) as '2000', week("2001-01-01",0) as '2001', week("2002-01-01",0) as '2002',week("2003-01-01",0) as '2003', week("2004-01-01",0) as '2004', week("2005-01-01",0) as '2005', week("2006-01-01",0) as '2006';
2000	2001	2002	2003	2004	2005	2006
0	0	0	0	0	0	1
select week("2000-01-06",0) as '2000', week("2001-01-06",0) as '2001', week("2002-01-06",0) as '2002',week("2003-01-06",0) as '2003', week("2004-01-06",0) as '2004', week("2005-01-06",0) as '2005', week("2006-01-06",0) as '2006';
2000	2001	2002	2003	2004	2005	2006
1	0	1	1	1	1	1
select week("2000-01-01",1) as '2000', week("2001-01-01",1) as '2001', week("2002-01-01",1) as '2002',week("2003-01-01",1) as '2003', week("2004-01-01",1) as '2004', week("2005-01-01",1) as '2005', week("2006-01-01",1) as '2006';
2000	2001	2002	2003	2004	2005	2006
0	1	1	1	1	0	0
select week("2000-01-06",1) as '2000', week("2001-01-06",1) as '2001', week("2002-01-06",1) as '2002',week("2003-01-06",1) as '2003', week("2004-01-06",1) as '2004', week("2005-01-06",1) as '2005', week("2006-01-06",1) as '2006';
2000	2001	2002	2003	2004	2005	2006
1	1	1	2	2	1	1
select yearweek("2000-01-01",0) as '2000', yearweek("2001-01-01",0) as '2001', yearweek("2002-01-01",0) as '2002',yearweek("2003-01-01",0) as '2003', yearweek("2004-01-01",0) as '2004', yearweek("2005-01-01",0) as '2005', yearweek("2006-01-01",0) as '2006';
2000	2001	2002	2003	2004	2005	2006
199952	200053	200152	200252	200352	200452	200601
select yearweek("2000-01-06",0) as '2000', yearweek("2001-01-06",0) as '2001', yearweek("2002-01-06",0) as '2002',yearweek("2003-01-06",0) as '2003', yearweek("2004-01-06",0) as '2004', yearweek("2005-01-06",0) as '2005', yearweek("2006-01-06",0) as '2006';
2000	2001	2002	2003	2004	2005	2006
200001	200053	200201	200301	200401	200501	200601
select yearweek("2000-01-01",1) as '2000', yearweek("2001-01-01",1) as '2001', yearweek("2002-01-01",1) as '2002',yearweek("2003-01-01",1) as '2003', yearweek("2004-01-01",1) as '2004', yearweek("2005-01-01",1) as '2005', yearweek("2006-01-01",1) as '2006';
2000	2001	2002	2003	2004	2005	2006
199952	200101	200201	200301	200401	200453	200552
select yearweek("2000-01-06",1) as '2000', yearweek("2001-01-06",1) as '2001', yearweek("2002-01-06",1) as '2002',yearweek("2003-01-06",1) as '2003', yearweek("2004-01-06",1) as '2004', yearweek("2005-01-06",1) as '2005', yearweek("2006-01-06",1) as '2006';
2000	2001	2002	2003	2004	2005	2006
200001	200101	200201	200302	200402	200501	200601
select week(19981231,2), week(19981231,3), week(20000101,2), week(20000101,3);
week(19981231,2)	week(19981231,3)	week(20000101,2)	week(20000101,3)
52	53	52	52
select week(20001231,2),week(20001231,3);
week(20001231,2)	week(20001231,3)
53	52
select week(19981231,0) as '0', week(19981231,1) as '1', week(19981231,2) as '2', week(19981231,3) as '3', week(19981231,4) as '4', week(19981231,5) as '5', week(19981231,6) as '6', week(19981231,7) as '7';
0	1	2	3	4	5	6	7
52	53	52	53	52	52	52	52
select week(20000101,0) as '0', week(20000101,1) as '1', week(20000101,2) as '2', week(20000101,3) as '3', week(20000101,4) as '4', week(20000101,5) as '5', week(20000101,6) as '6', week(20000101,7) as '7';
0	1	2	3	4	5	6	7
0	0	52	52	0	0	52	52
select week(20000106,0) as '0', week(20000106,1) as '1', week(20000106,2) as '2', week(20000106,3) as '3', week(20000106,4) as '4', week(20000106,5) as '5', week(20000106,6) as '6', week(20000106,7) as '7';
0	1	2	3	4	5	6	7
1	1	1	1	1	1	1	1
select week(20001231,0) as '0', week(20001231,1) as '1', week(20001231,2) as '2', week(20001231,3) as '3', week(20001231,4) as '4', week(20001231,5) as '5', week(20001231,6) as '6', week(20001231,7) as '7';
0	1	2	3	4	5	6	7
53	52	53	52	53	52	1	52
select week(20010101,0) as '0', week(20010101,1) as '1', week(20010101,2) as '2', week(20010101,3) as '3', week(20010101,4) as '4', week(20010101,5) as '5', week(20010101,6) as '6', week(20010101,7) as '7';
0	1	2	3	4	5	6	7
0	1	53	1	1	1	1	1
select yearweek(20001231,0), yearweek(20001231,1), yearweek(20001231,2), yearweek(20001231,3), yearweek(20001231,4), yearweek(20001231,5), yearweek(20001231,6), yearweek(20001231,7);
yearweek(20001231,0)	yearweek(20001231,1)	yearweek(20001231,2)	yearweek(20001231,3)	yearweek(20001231,4)	yearweek(20001231,5)	yearweek(20001231,6)	yearweek(20001231,7)
200053	200052	200053	200052	200101	200052	200101	200052
set default_week_format = 6;
select week(20001231), week(20001231,6);
week(20001231)	week(20001231,6)
1	1
set default_week_format = 0;
set default_week_format = 2;
select week(20001231),week(20001231,2),week(20001231,0);
week(20001231)	week(20001231,2)	week(20001231,0)
53	53	53
set default_week_format = 0;
select date_format('1998-12-31','%x-%v'),date_format('1999-01-01','%x-%v');
date_format('1998-12-31','%x-%v')	date_format('1999-01-01','%x-%v')
1998-53	1998-53
select date_format('1999-12-31','%x-%v'),date_format('2000-01-01','%x-%v');
date_format('1999-12-31','%x-%v')	date_format('2000-01-01','%x-%v')
1999-52	1999-52
select dayname("1962-03-03"),dayname("1962-03-03")+0;
dayname("1962-03-03")	dayname("1962-03-03")+0
Saturday	5
select monthname("1972-03-04"),monthname("1972-03-04")+0;
monthname("1972-03-04")	monthname("1972-03-04")+0
March	3
select time_format(19980131000000,'%H|%I|%k|%l|%i|%p|%r|%S|%T');
time_format(19980131000000,'%H|%I|%k|%l|%i|%p|%r|%S|%T')
00|12|0|12|00|AM|12:00:00 AM|00|00:00:00
select time_format(19980131010203,'%H|%I|%k|%l|%i|%p|%r|%S|%T');
time_format(19980131010203,'%H|%I|%k|%l|%i|%p|%r|%S|%T')
01|01|1|1|02|AM|01:02:03 AM|03|01:02:03
select time_format(19980131131415,'%H|%I|%k|%l|%i|%p|%r|%S|%T');
time_format(19980131131415,'%H|%I|%k|%l|%i|%p|%r|%S|%T')
13|01|13|1|14|PM|01:14:15 PM|15|13:14:15
select time_format(19980131010015,'%H|%I|%k|%l|%i|%p|%r|%S|%T');
time_format(19980131010015,'%H|%I|%k|%l|%i|%p|%r|%S|%T')
01|01|1|1|00|AM|01:00:15 AM|15|01:00:15
select date_format(concat('19980131',131415),'%H|%I|%k|%l|%i|%p|%r|%S|%T| %M|%W|%D|%Y|%y|%a|%b|%j|%m|%d|%h|%s|%w');
date_format(concat('19980131',131415),'%H|%I|%k|%l|%i|%p|%r|%S|%T| %M|%W|%D|%Y|%y|%a|%b|%j|%m|%d|%h|%s|%w')
13|01|13|1|14|PM|01:14:15 PM|15|13:14:15| January|Saturday|31st|1998|98|Sat|Jan|031|01|31|01|15|6
select date_format(19980021000000,'%H|%I|%k|%l|%i|%p|%r|%S|%T| %M|%W|%D|%Y|%y|%a|%b|%j|%m|%d|%h|%s|%w');
date_format(19980021000000,'%H|%I|%k|%l|%i|%p|%r|%S|%T| %M|%W|%D|%Y|%y|%a|%b|%j|%m|%d|%h|%s|%w')
NULL
select date_add("1997-12-31 23:59:59",INTERVAL 1 SECOND);
date_add("1997-12-31 23:59:59",INTERVAL 1 SECOND)
1998-01-01 00:00:00
select date_add("1997-12-31 23:59:59",INTERVAL 1 MINUTE);
date_add("1997-12-31 23:59:59",INTERVAL 1 MINUTE)
1998-01-01 00:00:59
select date_add("1997-12-31 23:59:59",INTERVAL 1 HOUR);
date_add("1997-12-31 23:59:59",INTERVAL 1 HOUR)
1998-01-01 00:59:59
select date_add("1997-12-31 23:59:59",INTERVAL 1 DAY);
date_add("1997-12-31 23:59:59",INTERVAL 1 DAY)
1998-01-01 23:59:59
select date_add("1997-12-31 23:59:59",INTERVAL 1 MONTH);
date_add("1997-12-31 23:59:59",INTERVAL 1 MONTH)
1998-01-31 23:59:59
select date_add("1997-12-31 23:59:59",INTERVAL 1 YEAR);
date_add("1997-12-31 23:59:59",INTERVAL 1 YEAR)
1998-12-31 23:59:59
select date_add("1997-12-31 23:59:59",INTERVAL "1:1" MINUTE_SECOND);
date_add("1997-12-31 23:59:59",INTERVAL "1:1" MINUTE_SECOND)
1998-01-01 00:01:00
select date_add("1997-12-31 23:59:59",INTERVAL "1:1" HOUR_MINUTE);
date_add("1997-12-31 23:59:59",INTERVAL "1:1" HOUR_MINUTE)
1998-01-01 01:00:59
select date_add("1997-12-31 23:59:59",INTERVAL "1:1" DAY_HOUR);
date_add("1997-12-31 23:59:59",INTERVAL "1:1" DAY_HOUR)
1998-01-02 00:59:59
select date_add("1997-12-31 23:59:59",INTERVAL "1 1" YEAR_MONTH);
date_add("1997-12-31 23:59:59",INTERVAL "1 1" YEAR_MONTH)
1999-01-31 23:59:59
select date_add("1997-12-31 23:59:59",INTERVAL "1:1:1" HOUR_SECOND);
date_add("1997-12-31 23:59:59",INTERVAL "1:1:1" HOUR_SECOND)
1998-01-01 01:01:00
select date_add("1997-12-31 23:59:59",INTERVAL "1 1:1" DAY_MINUTE);
date_add("1997-12-31 23:59:59",INTERVAL "1 1:1" DAY_MINUTE)
1998-01-02 01:00:59
select date_add("1997-12-31 23:59:59",INTERVAL "1 1:1:1" DAY_SECOND);
date_add("1997-12-31 23:59:59",INTERVAL "1 1:1:1" DAY_SECOND)
1998-01-02 01:01:00
select date_sub("1998-01-01 00:00:00",INTERVAL 1 SECOND);
date_sub("1998-01-01 00:00:00",INTERVAL 1 SECOND)
1997-12-31 23:59:59
select date_sub("1998-01-01 00:00:00",INTERVAL 1 MINUTE);
date_sub("1998-01-01 00:00:00",INTERVAL 1 MINUTE)
1997-12-31 23:59:00
select date_sub("1998-01-01 00:00:00",INTERVAL 1 HOUR);
date_sub("1998-01-01 00:00:00",INTERVAL 1 HOUR)
1997-12-31 23:00:00
select date_sub("1998-01-01 00:00:00",INTERVAL 1 DAY);
date_sub("1998-01-01 00:00:00",INTERVAL 1 DAY)
1997-12-31 00:00:00
select date_sub("1998-01-01 00:00:00",INTERVAL 1 MONTH);
date_sub("1998-01-01 00:00:00",INTERVAL 1 MONTH)
1997-12-01 00:00:00
select date_sub("1998-01-01 00:00:00",INTERVAL 1 YEAR);
date_sub("1998-01-01 00:00:00",INTERVAL 1 YEAR)
1997-01-01 00:00:00
select date_sub("1998-01-01 00:00:00",INTERVAL "1:1" MINUTE_SECOND);
date_sub("1998-01-01 00:00:00",INTERVAL "1:1" MINUTE_SECOND)
1997-12-31 23:58:59
select date_sub("1998-01-01 00:00:00",INTERVAL "1:1" HOUR_MINUTE);
date_sub("1998-01-01 00:00:00",INTERVAL "1:1" HOUR_MINUTE)
1997-12-31 22:59:00
select date_sub("1998-01-01 00:00:00",INTERVAL "1:1" DAY_HOUR);
date_sub("1998-01-01 00:00:00",INTERVAL "1:1" DAY_HOUR)
1997-12-30 23:00:00
select date_sub("1998-01-01 00:00:00",INTERVAL "1 1" YEAR_MONTH);
date_sub("1998-01-01 00:00:00",INTERVAL "1 1" YEAR_MONTH)
1996-12-01 00:00:00
select date_sub("1998-01-01 00:00:00",INTERVAL "1:1:1" HOUR_SECOND);
date_sub("1998-01-01 00:00:00",INTERVAL "1:1:1" HOUR_SECOND)
1997-12-31 22:58:59
select date_sub("1998-01-01 00:00:00",INTERVAL "1 1:1" DAY_MINUTE);
date_sub("1998-01-01 00:00:00",INTERVAL "1 1:1" DAY_MINUTE)
1997-12-30 22:59:00
select date_sub("1998-01-01 00:00:00",INTERVAL "1 1:1:1" DAY_SECOND);
date_sub("1998-01-01 00:00:00",INTERVAL "1 1:1:1" DAY_SECOND)
1997-12-30 22:58:59
select date_add("1997-12-31 23:59:59",INTERVAL 100000 SECOND);
date_add("1997-12-31 23:59:59",INTERVAL 100000 SECOND)
1998-01-02 03:46:39
select date_add("1997-12-31 23:59:59",INTERVAL -100000 MINUTE);
date_add("1997-12-31 23:59:59",INTERVAL -100000 MINUTE)
1997-10-23 13:19:59
select date_add("1997-12-31 23:59:59",INTERVAL 100000 HOUR);
date_add("1997-12-31 23:59:59",INTERVAL 100000 HOUR)
2009-05-29 15:59:59
select date_add("1997-12-31 23:59:59",INTERVAL -100000 DAY);
date_add("1997-12-31 23:59:59",INTERVAL -100000 DAY)
1724-03-17 23:59:59
select date_add("1997-12-31 23:59:59",INTERVAL 100000 MONTH);
date_add("1997-12-31 23:59:59",INTERVAL 100000 MONTH)
NULL
select date_add("1997-12-31 23:59:59",INTERVAL -100000 YEAR);
date_add("1997-12-31 23:59:59",INTERVAL -100000 YEAR)
NULL
select date_add("1997-12-31 23:59:59",INTERVAL "10000:1" MINUTE_SECOND);
date_add("1997-12-31 23:59:59",INTERVAL "10000:1" MINUTE_SECOND)
1998-01-07 22:40:00
select date_add("1997-12-31 23:59:59",INTERVAL "-10000:1" HOUR_MINUTE);
date_add("1997-12-31 23:59:59",INTERVAL "-10000:1" HOUR_MINUTE)
1996-11-10 07:58:59
select date_add("1997-12-31 23:59:59",INTERVAL "10000:1" DAY_HOUR);
date_add("1997-12-31 23:59:59",INTERVAL "10000:1" DAY_HOUR)
2025-05-19 00:59:59
select date_add("1997-12-31 23:59:59",INTERVAL "-100 1" YEAR_MONTH);
date_add("1997-12-31 23:59:59",INTERVAL "-100 1" YEAR_MONTH)
1897-11-30 23:59:59
select date_add("1997-12-31 23:59:59",INTERVAL "10000:99:99" HOUR_SECOND);
date_add("1997-12-31 23:59:59",INTERVAL "10000:99:99" HOUR_SECOND)
1999-02-21 17:40:38
select date_add("1997-12-31 23:59:59",INTERVAL " -10000 99:99" DAY_MINUTE);
date_add("1997-12-31 23:59:59",INTERVAL " -10000 99:99" DAY_MINUTE)
1970-08-11 19:20:59
select date_add("1997-12-31 23:59:59",INTERVAL "10000 99:99:99" DAY_SECOND);
date_add("1997-12-31 23:59:59",INTERVAL "10000 99:99:99" DAY_SECOND)
2025-05-23 04:40:38
select "1997-12-31 23:59:59" + INTERVAL 1 SECOND;
"1997-12-31 23:59:59" + INTERVAL 1 SECOND
1998-01-01 00:00:00
select INTERVAL 1 DAY + "1997-12-31";
INTERVAL 1 DAY + "1997-12-31"
1998-01-01
select "1998-01-01 00:00:00" - INTERVAL 1 SECOND;
"1998-01-01 00:00:00" - INTERVAL 1 SECOND
1997-12-31 23:59:59
select date_sub("1998-01-02",INTERVAL 31 DAY);
date_sub("1998-01-02",INTERVAL 31 DAY)
1997-12-02
select date_add("1997-12-31",INTERVAL 1 SECOND);
date_add("1997-12-31",INTERVAL 1 SECOND)
1997-12-31 00:00:01
select date_add("1997-12-31",INTERVAL 1 DAY);
date_add("1997-12-31",INTERVAL 1 DAY)
1998-01-01
select date_add(NULL,INTERVAL 100000 SECOND);
date_add(NULL,INTERVAL 100000 SECOND)
NULL
select date_add("1997-12-31 23:59:59",INTERVAL NULL SECOND);
date_add("1997-12-31 23:59:59",INTERVAL NULL SECOND)
NULL
select date_add("1997-12-31 23:59:59",INTERVAL NULL MINUTE_SECOND);
date_add("1997-12-31 23:59:59",INTERVAL NULL MINUTE_SECOND)
NULL
select date_add("9999-12-31 23:59:59",INTERVAL 1 SECOND);
date_add("9999-12-31 23:59:59",INTERVAL 1 SECOND)
NULL
select date_sub("0000-00-00 00:00:00",INTERVAL 1 SECOND);
date_sub("0000-00-00 00:00:00",INTERVAL 1 SECOND)
NULL
select date_add('1998-01-30',Interval 1 month);
date_add('1998-01-30',Interval 1 month)
1998-02-28
select date_add('1998-01-30',Interval '2:1' year_month);
date_add('1998-01-30',Interval '2:1' year_month)
2000-02-29
select date_add('1996-02-29',Interval '1' year);
date_add('1996-02-29',Interval '1' year)
1997-02-28
select extract(YEAR FROM "1999-01-02 10:11:12");
extract(YEAR FROM "1999-01-02 10:11:12")
1999
select extract(YEAR_MONTH FROM "1999-01-02");
extract(YEAR_MONTH FROM "1999-01-02")
199901
select extract(DAY FROM "1999-01-02");
extract(DAY FROM "1999-01-02")
2
select extract(DAY_HOUR FROM "1999-01-02 10:11:12");
extract(DAY_HOUR FROM "1999-01-02 10:11:12")
210
select extract(DAY_MINUTE FROM "02 10:11:12");
extract(DAY_MINUTE FROM "02 10:11:12")
21011
select extract(DAY_SECOND FROM "225 10:11:12");
extract(DAY_SECOND FROM "225 10:11:12")
225101112
select extract(HOUR FROM "1999-01-02 10:11:12");
extract(HOUR FROM "1999-01-02 10:11:12")
10
select extract(HOUR_MINUTE FROM "10:11:12");
extract(HOUR_MINUTE FROM "10:11:12")
1011
select extract(HOUR_SECOND FROM "10:11:12");
extract(HOUR_SECOND FROM "10:11:12")
101112
select extract(MINUTE FROM "10:11:12");
extract(MINUTE FROM "10:11:12")
11
select extract(MINUTE_SECOND FROM "10:11:12");
extract(MINUTE_SECOND FROM "10:11:12")
1112
select extract(SECOND FROM "1999-01-02 10:11:12");
extract(SECOND FROM "1999-01-02 10:11:12")
12
select extract(MONTH FROM "2001-02-00");
extract(MONTH FROM "2001-02-00")
2
SELECT "1900-01-01 00:00:00" + INTERVAL 2147483648 SECOND;
"1900-01-01 00:00:00" + INTERVAL 2147483648 SECOND
1968-01-20 03:14:08
SELECT "1900-01-01 00:00:00" + INTERVAL "1:2147483647" MINUTE_SECOND;
"1900-01-01 00:00:00" + INTERVAL "1:2147483647" MINUTE_SECOND
1968-01-20 03:15:07
SELECT "1900-01-01 00:00:00" + INTERVAL "100000000:214748364700" MINUTE_SECOND;
"1900-01-01 00:00:00" + INTERVAL "100000000:214748364700" MINUTE_SECOND
8895-03-27 22:11:40
SELECT "1900-01-01 00:00:00" + INTERVAL 1<<37 SECOND;
"1900-01-01 00:00:00" + INTERVAL 1<<37 SECOND
6255-04-08 15:04:32
SELECT "1900-01-01 00:00:00" + INTERVAL 1<<31 MINUTE;
"1900-01-01 00:00:00" + INTERVAL 1<<31 MINUTE
5983-01-24 02:08:00
SELECT "1900-01-01 00:00:00" + INTERVAL 1<<20 HOUR;
"1900-01-01 00:00:00" + INTERVAL 1<<20 HOUR
2019-08-15 16:00:00
SELECT "1900-01-01 00:00:00" + INTERVAL 1<<38 SECOND;
"1900-01-01 00:00:00" + INTERVAL 1<<38 SECOND
NULL
SELECT "1900-01-01 00:00:00" + INTERVAL 1<<33 MINUTE;
"1900-01-01 00:00:00" + INTERVAL 1<<33 MINUTE
NULL
SELECT "1900-01-01 00:00:00" + INTERVAL 1<<30 HOUR;
"1900-01-01 00:00:00" + INTERVAL 1<<30 HOUR
NULL
SELECT "1900-01-01 00:00:00" + INTERVAL "1000000000:214748364700" MINUTE_SECOND;
"1900-01-01 00:00:00" + INTERVAL "1000000000:214748364700" MINUTE_SECOND
NULL
create table t1 (ctime varchar(20));
insert into t1 values ('2001-01-12 12:23:40');
select ctime, hour(ctime) from t1;
ctime	hour(ctime)
2001-01-12 12:23:40	12
select ctime from t1 where extract(MONTH FROM ctime) = 1 AND extract(YEAR FROM ctime) = 2001;
ctime
2001-01-12 12:23:40
drop table t1;
create table t1 (id int);
create table t2 (id int, date date);
insert into t1 values (1);
insert into t2 values (1, "0000-00-00");
insert into t1 values (2);
insert into t2 values (2, "2000-01-01");
select monthname(date) from t1 inner join t2 on t1.id = t2.id;
monthname(date)
NULL
January
select monthname(date) from t1 inner join t2 on t1.id = t2.id order by t1.id;
monthname(date)
NULL
January
drop table t1,t2;
CREATE TABLE t1 (updated text) ENGINE=MyISAM;
INSERT INTO t1 VALUES ('');
SELECT month(updated) from t1;
month(updated)
NULL
Warnings:
Warning	1292	Truncated incorrect datetime value: ''
SELECT year(updated) from t1;
year(updated)
NULL
Warnings:
Warning	1292	Truncated incorrect datetime value: ''
drop table t1;
create table t1 (d date, dt datetime, t timestamp, c char(10));
insert into t1 values ("0000-00-00", "0000-00-00", "0000-00-00", "0000-00-00");
select dayofyear("0000-00-00"),dayofyear(d),dayofyear(dt),dayofyear(t),dayofyear(c) from t1;
dayofyear("0000-00-00")	dayofyear(d)	dayofyear(dt)	dayofyear(t)	dayofyear(c)
NULL	NULL	NULL	NULL	NULL
select dayofmonth("0000-00-00"),dayofmonth(d),dayofmonth(dt),dayofmonth(t),dayofmonth(c) from t1;
dayofmonth("0000-00-00")	dayofmonth(d)	dayofmonth(dt)	dayofmonth(t)	dayofmonth(c)
0	0	0	0	0
select month("0000-00-00"),month(d),month(dt),month(t),month(c) from t1;
month("0000-00-00")	month(d)	month(dt)	month(t)	month(c)
0	0	0	0	0
select quarter("0000-00-00"),quarter(d),quarter(dt),quarter(t),quarter(c) from t1;
quarter("0000-00-00")	quarter(d)	quarter(dt)	quarter(t)	quarter(c)
0	0	0	0	0
select week("0000-00-00"),week(d),week(dt),week(t),week(c) from t1;
week("0000-00-00")	week(d)	week(dt)	week(t)	week(c)
NULL	NULL	NULL	NULL	NULL
select year("0000-00-00"),year(d),year(dt),year(t),year(c) from t1;
year("0000-00-00")	year(d)	year(dt)	year(t)	year(c)
0	0	0	0	0
select yearweek("0000-00-00"),yearweek(d),yearweek(dt),yearweek(t),yearweek(c) from t1;
yearweek("0000-00-00")	yearweek(d)	yearweek(dt)	yearweek(t)	yearweek(c)
NULL	NULL	NULL	NULL	NULL
select to_days("0000-00-00"),to_days(d),to_days(dt),to_days(t),to_days(c) from t1;
to_days("0000-00-00")	to_days(d)	to_days(dt)	to_days(t)	to_days(c)
NULL	NULL	NULL	NULL	NULL
select extract(MONTH FROM "0000-00-00"),extract(MONTH FROM d),extract(MONTH FROM dt),extract(MONTH FROM t),extract(MONTH FROM c) from t1;
extract(MONTH FROM "0000-00-00")	extract(MONTH FROM d)	extract(MONTH FROM dt)	extract(MONTH FROM t)	extract(MONTH FROM c)
0	0	0	0	0
drop table t1;
CREATE TABLE t1 ( start datetime default NULL);
INSERT INTO t1 VALUES ('2002-10-21 00:00:00'),('2002-10-28 00:00:00'),('2002-11-04 00:00:00');
CREATE TABLE t2 ( ctime1 timestamp(14) NOT NULL, ctime2 timestamp(14) NOT NULL);
INSERT INTO t2 VALUES (20021029165106,20021105164731);
CREATE TABLE t3 (ctime1 char(19) NOT NULL, ctime2 char(19) NOT NULL);
INSERT INTO t3 VALUES ("2002-10-29 16:51:06","2002-11-05 16:47:31");
select * from t1, t2 where t1.start between t2.ctime1 and t2.ctime2;
start	ctime1	ctime2
2002-11-04 00:00:00	2002-10-29 16:51:06	2002-11-05 16:47:31
select * from t1, t2 where t1.start >= t2.ctime1 and t1.start <= t2.ctime2;
start	ctime1	ctime2
2002-11-04 00:00:00	2002-10-29 16:51:06	2002-11-05 16:47:31
select * from t1, t3 where t1.start between t3.ctime1 and t3.ctime2;
start	ctime1	ctime2
2002-11-04 00:00:00	2002-10-29 16:51:06	2002-11-05 16:47:31
drop table t1,t2,t3;
select @a:=FROM_UNIXTIME(1);
@a:=FROM_UNIXTIME(1)
1970-01-01 03:00:01
select unix_timestamp(@a);
unix_timestamp(@a)
1
select unix_timestamp('1969-12-01 19:00:01');
unix_timestamp('1969-12-01 19:00:01')
0
select from_unixtime(-1);
from_unixtime(-1)
NULL
select from_unixtime(2145916800);
from_unixtime(2145916800)
NULL
select from_unixtime(0);
from_unixtime(0)
1970-01-01 03:00:00
CREATE TABLE t1 (datetime datetime, timestamp timestamp, date date, time time);
INSERT INTO t1 values ("2001-01-02 03:04:05", "2002-01-02 03:04:05", "2003-01-02", "06:07:08");
SELECT * from t1;
datetime	timestamp	date	time
2001-01-02 03:04:05	2002-01-02 03:04:05	2003-01-02	06:07:08
select date_add("1997-12-31",INTERVAL 1 SECOND);
date_add("1997-12-31",INTERVAL 1 SECOND)
1997-12-31 00:00:01
select date_add("1997-12-31",INTERVAL "1 1" YEAR_MONTH);
date_add("1997-12-31",INTERVAL "1 1" YEAR_MONTH)
1999-01-31
select date_add(datetime, INTERVAL 1 SECOND) from t1;
date_add(datetime, INTERVAL 1 SECOND)
2001-01-02 03:04:06
select date_add(datetime, INTERVAL 1 YEAR) from t1;
date_add(datetime, INTERVAL 1 YEAR)
2002-01-02 03:04:05
select date_add(date,INTERVAL 1 SECOND) from t1;
date_add(date,INTERVAL 1 SECOND)
2003-01-02 00:00:01
select date_add(date,INTERVAL 1 MINUTE) from t1;
date_add(date,INTERVAL 1 MINUTE)
2003-01-02 00:01:00
select date_add(date,INTERVAL 1 HOUR) from t1;
date_add(date,INTERVAL 1 HOUR)
2003-01-02 01:00:00
select date_add(date,INTERVAL 1 DAY) from t1;
date_add(date,INTERVAL 1 DAY)
2003-01-03
select date_add(date,INTERVAL 1 MONTH) from t1;
date_add(date,INTERVAL 1 MONTH)
2003-02-02
select date_add(date,INTERVAL 1 YEAR) from t1;
date_add(date,INTERVAL 1 YEAR)
2004-01-02
select date_add(date,INTERVAL "1:1" MINUTE_SECOND) from t1;
date_add(date,INTERVAL "1:1" MINUTE_SECOND)
2003-01-02 00:01:01
select date_add(date,INTERVAL "1:1" HOUR_MINUTE) from t1;
date_add(date,INTERVAL "1:1" HOUR_MINUTE)
2003-01-02 01:01:00
select date_add(date,INTERVAL "1:1" DAY_HOUR) from t1;
date_add(date,INTERVAL "1:1" DAY_HOUR)
2003-01-03 01:00:00
select date_add(date,INTERVAL "1 1" YEAR_MONTH) from t1;
date_add(date,INTERVAL "1 1" YEAR_MONTH)
2004-02-02
select date_add(date,INTERVAL "1:1:1" HOUR_SECOND) from t1;
date_add(date,INTERVAL "1:1:1" HOUR_SECOND)
2003-01-02 01:01:01
select date_add(date,INTERVAL "1 1:1" DAY_MINUTE) from t1;
date_add(date,INTERVAL "1 1:1" DAY_MINUTE)
2003-01-03 01:01:00
select date_add(date,INTERVAL "1 1:1:1" DAY_SECOND) from t1;
date_add(date,INTERVAL "1 1:1:1" DAY_SECOND)
2003-01-03 01:01:01
select date_add(time,INTERVAL 1 SECOND) from t1;
date_add(time,INTERVAL 1 SECOND)
NULL
Warnings:
Warning	1264	Data truncated; out of range for column 'time' at row 1
drop table t1;
select last_day('2000-02-05') as f1, last_day('2002-12-31') as f2,
last_day('2003-03-32') as f3, last_day('2003-04-01') as f4,
last_day('2001-01-01 01:01:01') as f5, last_day(NULL),
last_day('2001-02-12');
f1	f2	f3	f4	f5	last_day(NULL)	last_day('2001-02-12')
2000-02-29	2002-12-31	NULL	2003-04-30	2001-01-31	NULL	2001-02-28
Warnings:
Warning	1292	Truncated incorrect datetime value: '2003-03-32'
create table t1 select last_day('2000-02-05') as a,
from_days(to_days("960101")) as b;
describe t1;
Field	Type	Null	Key	Default	Extra
a	date			0000-00-00	
b	date	YES		NULL	
select * from t1;
a	b
2000-02-29	1996-01-01
drop table t1;
select last_day('2000-02-05') as a,
from_days(to_days("960101")) as b;
a	b
2000-02-29	1996-01-01
select date_add(last_day("1997-12-1"), INTERVAL 1 DAY);
date_add(last_day("1997-12-1"), INTERVAL 1 DAY)
1998-01-01
select length(last_day("1997-12-1"));
length(last_day("1997-12-1"))
10
select last_day("1997-12-1")+0;
last_day("1997-12-1")+0
19971231
select last_day("1997-12-1")+0.0;
last_day("1997-12-1")+0.0
19971231.0
select strcmp(date_sub(localtimestamp(), interval 3 hour), utc_timestamp())=0;
strcmp(date_sub(localtimestamp(), interval 3 hour), utc_timestamp())=0
1
select strcmp(date_format(date_sub(localtimestamp(), interval 3 hour),"%T"), utc_time())=0;
strcmp(date_format(date_sub(localtimestamp(), interval 3 hour),"%T"), utc_time())=0
1
select strcmp(date_format(date_sub(localtimestamp(), interval 3 hour),"%Y-%m-%d"), utc_date())=0;
strcmp(date_format(date_sub(localtimestamp(), interval 3 hour),"%Y-%m-%d"), utc_date())=0
1
select strcmp(date_format(utc_timestamp(),"%T"), utc_time())=0;
strcmp(date_format(utc_timestamp(),"%T"), utc_time())=0
1
select strcmp(date_format(utc_timestamp(),"%Y-%m-%d"), utc_date())=0;
strcmp(date_format(utc_timestamp(),"%Y-%m-%d"), utc_date())=0
1
select strcmp(concat(utc_date(),' ',utc_time()),utc_timestamp())=0;
strcmp(concat(utc_date(),' ',utc_time()),utc_timestamp())=0
1
explain extended select period_add("9602",-12),period_diff(199505,"9404"),from_days(to_days("960101")),dayofmonth("1997-01-02"), month("1997-01-02"), monthname("1972-03-04"),dayofyear("0000-00-00"),HOUR("1997-03-03 23:03:22"),MINUTE("23:03:22"),SECOND(230322),QUARTER(980303),WEEK("1998-03-03"),yearweek("2000-01-01",1),week(19950101,1),year("98-02-03"),weekday(curdate())-weekday(now()),dayname("1962-03-03"),unix_timestamp(),sec_to_time(time_to_sec("0:30:47")/6.21),curtime(),utc_time(),curdate(),utc_date(),utc_timestamp(),date_format("1997-01-02 03:04:05", "%M %W %D %Y %y %m %d %h %i %s %w"),from_unixtime(unix_timestamp("1994-03-02 10:11:12")),"1997-12-31 23:59:59" + INTERVAL 1 SECOND,"1998-01-01 00:00:00" - INTERVAL 1 SECOND,INTERVAL 1 DAY + "1997-12-31", extract(YEAR FROM "1999-01-02 10:11:12"),date_add("1997-12-31 23:59:59",INTERVAL 1 SECOND);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
Warnings:
Note	1003	select sql_no_cache period_add(_latin1'9602',-(12)) AS `period_add("9602",-12)`,period_diff(199505,_latin1'9404') AS `period_diff(199505,"9404")`,from_days(to_days(_latin1'960101')) AS `from_days(to_days("960101"))`,dayofmonth(_latin1'1997-01-02') AS `dayofmonth("1997-01-02")`,month(_latin1'1997-01-02') AS `month("1997-01-02")`,monthname(_latin1'1972-03-04') AS `monthname("1972-03-04")`,dayofyear(_latin1'0000-00-00') AS `dayofyear("0000-00-00")`,hour(_latin1'1997-03-03 23:03:22') AS `HOUR("1997-03-03 23:03:22")`,minute(_latin1'23:03:22') AS `MINUTE("23:03:22")`,second(230322) AS `SECOND(230322)`,quarter(980303) AS `QUARTER(980303)`,week(_latin1'1998-03-03',0) AS `WEEK("1998-03-03")`,yearweek(_latin1'2000-01-01',1) AS `yearweek("2000-01-01",1)`,week(19950101,1) AS `week(19950101,1)`,year(_latin1'98-02-03') AS `year("98-02-03")`,(weekday(to_days(curdate())) - weekday(to_days(now()))) AS `weekday(curdate())-weekday(now())`,dayname(to_days(_latin1'1962-03-03')) AS `dayname("1962-03-03")`,unix_timestamp() AS `unix_timestamp()`,sec_to_time((time_to_sec(_latin1'0:30:47') / 6.21)) AS `sec_to_time(time_to_sec("0:30:47")/6.21)`,curtime() AS `curtime()`,utc_time() AS `utc_time()`,curdate() AS `curdate()`,utc_date() AS `utc_date()`,utc_timestamp() AS `utc_timestamp()`,date_format(_latin1'1997-01-02 03:04:05',_latin1'%M %W %D %Y %y %m %d %h %i %s %w') AS `date_format("1997-01-02 03:04:05", "%M %W %D %Y %y %m %d %h %i %s %w")`,from_unixtime(unix_timestamp(_latin1'1994-03-02 10:11:12')) AS `from_unixtime(unix_timestamp("1994-03-02 10:11:12"))`,(_latin1'1997-12-31 23:59:59' + interval 1 second) AS `"1997-12-31 23:59:59" + INTERVAL 1 SECOND`,(_latin1'1998-01-01 00:00:00' - interval 1 second) AS `"1998-01-01 00:00:00" - INTERVAL 1 SECOND`,(_latin1'1997-12-31' + interval 1 day) AS `INTERVAL 1 DAY + "1997-12-31"`,extract(year from _latin1'1999-01-02 10:11:12') AS `extract(YEAR FROM "1999-01-02 10:11:12")`,(_latin1'1997-12-31 23:59:59' + interval 1 second) AS `date_add("1997-12-31 23:59:59",INTERVAL 1 SECOND)`
SET @TMP=NOW();
CREATE TABLE t1 (d DATETIME);
INSERT INTO t1 VALUES (NOW());
INSERT INTO t1 VALUES (NOW());
INSERT INTO t1 VALUES (NOW());
SELECT count(*) FROM t1 WHERE d>FROM_DAYS(TO_DAYS(@TMP)) AND d<=FROM_DAYS(TO_DAYS(@TMP)+1);
count(*)
3
DROP TABLE t1;