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) 1 52 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 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 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) TYPE=MyISAM; INSERT INTO t1 VALUES (''); SELECT month(updated) from t1; month(updated) NULL SELECT year(updated) from t1; year(updated) NULL 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 20021029165106 20021105164731 select * from t1, t2 where t1.start >= t2.ctime1 and t1.start <= t2.ctime2; start ctime1 ctime2 2002-11-04 00:00:00 20021029165106 20021105164731 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;