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drop table if exists t1;
create table t1 (t datetime);
insert into t1 values(101),(691231),(700101),(991231),(10000101),(99991231),(101000000),(691231000000),(700101000000),(991231235959),(10000101000000),(99991231235959),(20030102030460),(20030102036301),(20030102240401),(20030132030401),(20031302030460);
Warnings:
Warning 1265 Data truncated for column 't' at row 13
Warning 1265 Data truncated for column 't' at row 14
Warning 1265 Data truncated for column 't' at row 15
Warning 1265 Data truncated for column 't' at row 16
Warning 1265 Data truncated for column 't' at row 17
select * from t1;
t
2000-01-01 00:00:00
2069-12-31 00:00:00
1970-01-01 00:00:00
1999-12-31 00:00:00
1000-01-01 00:00:00
9999-12-31 00:00:00
2000-01-01 00:00:00
2069-12-31 00:00:00
1970-01-01 00:00:00
1999-12-31 23:59:59
1000-01-01 00:00:00
9999-12-31 23:59:59
0000-00-00 00:00:00
0000-00-00 00:00:00
0000-00-00 00:00:00
0000-00-00 00:00:00
0000-00-00 00:00:00
delete from t1 where t > 0;
optimize table t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
delete from t1;
insert into t1 values("000101"),("691231"),("700101"),("991231"),("00000101"),("00010101"),("99991231"),("00101000000"),("691231000000"),("700101000000"),("991231235959"),("10000101000000"),("99991231235959"),("20030102030460"),("20030102036301"),("20030102240401"),("20030132030401"),("20031302030460");
select * from t1;
t
2000-01-01 00:00:00
2069-12-31 00:00:00
1970-01-01 00:00:00
1999-12-31 00:00:00
0000-01-01 00:00:00
0001-01-01 00:00:00
9999-12-31 00:00:00
2000-10-10 00:00:00
2069-12-31 00:00:00
1970-01-01 00:00:00
1999-12-31 23:59:59
1000-01-01 00:00:00
9999-12-31 23:59:59
0000-00-00 00:00:00
0000-00-00 00:00:00
0000-00-00 00:00:00
0000-00-00 00:00:00
0000-00-00 00:00:00
drop table t1;
CREATE TABLE t1 (a timestamp, b date, c time, d datetime);
insert into t1 (b,c,d) values(now(),curtime(),now());
select date_format(a,"%Y-%m-%d")=b,right(a+0,6)=c+0,a=d+0 from t1;
date_format(a,"%Y-%m-%d")=b right(a+0,6)=c+0 a=d+0
1 1 1
drop table t1;
CREATE TABLE t1 (a datetime not null);
insert into t1 values (0);
select * from t1 where a is null;
a
0000-00-00 00:00:00
drop table t1;
create table t1 (id int, dt datetime);
insert into t1 values (1,"2001-08-14 00:00:00"),(2,"2001-08-15 00:00:00"),(3,"2001-08-16 00:00:00"),(4,"2003-09-15 01:20:30");
select * from t1 where dt='2001-08-14 00:00:00' and dt = if(id=1,'2001-08-14 00:00:00','1999-08-15');
id dt
1 2001-08-14 00:00:00
create index dt on t1 (dt);
select * from t1 where dt > 20021020;
id dt
4 2003-09-15 01:20:30
select * from t1 ignore index (dt) where dt > 20021020;
id dt
4 2003-09-15 01:20:30
drop table t1;
CREATE TABLE `t1` (
`date` datetime NOT NULL default '0000-00-00 00:00:00',
`numfacture` int(6) unsigned NOT NULL default '0',
`expedition` datetime NOT NULL default '0000-00-00 00:00:00',
PRIMARY KEY (`numfacture`),
KEY `date` (`date`),
KEY `expedition` (`expedition`)
) ENGINE=MyISAM;
INSERT INTO t1 (expedition) VALUES ('0001-00-00 00:00:00');
SELECT * FROM t1 WHERE expedition='0001-00-00 00:00:00';
date numfacture expedition
0000-00-00 00:00:00 0 0001-00-00 00:00:00
INSERT INTO t1 (numfacture,expedition) VALUES ('1212','0001-00-00 00:00:00');
SELECT * FROM t1 WHERE expedition='0001-00-00 00:00:00';
date numfacture expedition
0000-00-00 00:00:00 0 0001-00-00 00:00:00
0000-00-00 00:00:00 1212 0001-00-00 00:00:00
EXPLAIN SELECT * FROM t1 WHERE expedition='0001-00-00 00:00:00';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref expedition expedition 8 const 1 Using where
drop table t1;
create table t1 (a datetime not null, b datetime not null);
insert into t1 values (now(), now());
insert into t1 values (now(), now());
select * from t1 where a is null or b is null;
a b
drop table t1;
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