【MySQL-5.7】日期与时间类型
MySQL中的日期与时间类型，主要包括：YEAR、TIME、DATE、DATETIME、TIMESTAMP，下表中列出了这几种类型的属性。
类型名称 |
日期格式 |
日期范围 |
占用空间 |
YEAR |
YYYY |
1901 ~ 2155 |
1字节 |
TIME |
HH:MM:SS |
-838:59:59 ~ 838:59:59 |
3字节 |
DATE |
YYYY-MM-DD |
1000-01-01 ~ 9999-12-3 |
3字节 |
DATETIME |
YYYY-MM-DD HH:MM:SS |
1000-01-01 00:00:00 ~ 9999-12-31 23:59:59 |
8字节 |
TIMESTAMP |
YYYY-MM-DD HH:MM:SS |
1970-01-01 00:00:01 UTC ~ 2038-01-19 03:14:07 UTC |
4字节 |
一、YEAR
YEAR类型可以使用三种格式表示：
1. 以4位数字或字符串表示，两者效果相同，表示范围1901~2155，插入超出范围的数据会报错。
2. 以2位字符串格式表示，范围为‘00’~‘99’。‘00’~‘69’表示2000~2069，‘70’~‘99’表示1970~1999。‘0’和‘00’都会被识别为2000，超出范围的数据也会被识别为2000。
3. 以2位数字格式表示，范围为1~99。1~69表示2001~2069,70~99表示1970~1999。但0值会被识别为0000，这和2位字符串被识别为2000有所不同。
下面是以上三种表示格式的例子：
mysql> create table test1 (id year);
Query OK, 0 rows affected (0.04 sec)
mysql> desc test1;
+-------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id | year(4) | YES | | NULL | |
+-------+---------+------+-----+---------+-------+
1 row in set (0.01 sec)（1）以4位字符串或数字格式表示
mysql> insert into test1 values (2010),('2010');
Query OK, 2 rows affected (0.02 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> select * from test1;
+------+
| id |
+------+
| 2010 |
| 2010 |
+------+
2 rows in set (0.00 sec)
mysql> insert into test1 values (2156);
ERROR 1264 (22003): Out of range value for column 'id' at row 1（2）以2位字符串格式表示
mysql> truncate table test1;
Query OK, 0 rows affected (0.04 sec)
mysql> insert into test1 values ('0'),('00'),('10'),('77');
Query OK, 4 rows affected (0.03 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> select * from test1;
+------+
| id |
+------+
| 2000 |
| 2000 |
| 2010 |
| 1977 |
+------+
4 rows in set (0.00 sec)（3）以2位数字格式表示
mysql> truncate table test1;
Query OK, 0 rows affected (0.02 sec)
mysql> insert into test1 values (0),(00),(10),(77);
Query OK, 4 rows affected (0.01 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> select * from test1;
+------+
| id |
+------+
| 0000 |
| 0000 |
| 2010 |
| 1977 |
+------+
4 rows in set (0.00 sec)二、TIME
TIME类型可以用多种格式表示，如：
‘D HH:MM:SS':D表示天数，在插入表中时会折算成小时，即：D*24+HH:MM:SS。
'HHMMSS':省略冒号，但各个时间要有意义，比如‘128012’分钟部分会被识别为‘12：80：12’，80分钟是没有意义的，插入会报错。
'HH:MM':表示小时分钟，如‘12:08’表示12小时8分钟。
'SS':表示秒。
需要注意的是：如果输入‘1208’，虽然我们想让MySQL识别为12小时8分钟，但在这种格式下，MySQL识别为‘00:12:08’。
下面是几个例子：
mysql> create table test2 (id time);
Query OK, 0 rows affected (0.32 sec)
mysql> desc test2;
+-------+------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+------+------+-----+---------+-------+
| id | time | YES | | NULL | |
+-------+------+------+-----+---------+-------+
1 row in set (0.02 sec)mysql> insert into test2 values ('10:47:23'),('23:13'),('2 11:11'),('3 05'),('10');
Query OK, 5 rows affected (0.10 sec)
Records: 5 Duplicates: 0 Warnings: 0
mysql> select * from test2;
+----------+
| id |
+----------+
| 10:47:23 |
| 23:13:00 |
| 59:11:00 |
| 77:00:00 |
| 00:00:10 |
+----------+
5 rows in set (0.00 sec)
mysql> insert into test2 values ('3 5');
ERROR 1292 (22007): Incorrect time value: '3 5' for column 'id' at row 1mysql> truncate table test2;
Query OK, 0 rows affected (0.24 sec)
mysql> insert into test2 values ('105821'),(105821),('0');
Query OK, 3 rows affected (0.10 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> insert into test2 values (108013);
ERROR 1292 (22007): Incorrect time value: '108013' for column 'id' at row 1
mysql> select * from test2;
+----------+
| id |
+----------+
| 10:58:21 |
| 10:58:21 |
| 00:00:00 |
+----------+
3 rows in set (0.00 sec)三、DATE
DATE类型可以通过如下格式表示：
‘YYYY-MM-DD','YYYYMMDD',YYYYMMDD,'YY-MM-DD','YYMMDD',YYMMDD
其中当使用两位表示年份时，分00~69和70~99两种，参考YEAR类型。
下面是几个DATE类型的例子：
mysql> create table test3 (id date);
Query OK, 0 rows affected (0.25 sec)
mysql> desc test3;
+-------+------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+------+------+-----+---------+-------+
| id | date | YES | | NULL | |
+-------+------+------+-----+---------+-------+
1 row in set (0.02 sec)mysql> insert into test3 values ('1992-03-08'),('19920308'),(19920308);
Query OK, 3 rows affected (0.11 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> select * from test3;
+------------+
| id |
+------------+
| 1992-03-08 |
| 1992-03-08 |
| 1992-03-08 |
+------------+
3 rows in set (0.00 sec)mysql> truncate table test3;
Query OK, 0 rows affected (0.23 sec)
mysql> insert into test3 values ('92-03-08'),('920308'),(920308),('10-12-20');
Query OK, 4 rows affected (0.09 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> select * from test3;
+------------+
| id |
+------------+
| 1992-03-08 |
| 1992-03-08 |
| 1992-03-08 |
| 2010-12-20 |
+------------+
4 rows in set (0.00 sec)四、DATETIME
DATETIME类型，包含日期和时间部分。可以使用引号字符串或数字两种，年份可以是4位，也可以是2位，在此不再赘述，请参照上面的DATE和TIME类型。下面是几个例子：
mysql> create table test4 (id datetime);
Query OK, 0 rows affected (0.30 sec)
mysql> desc test4;
+-------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| id | datetime | YES | | NULL | |
+-------+----------+------+-----+---------+-------+
1 row in set (0.01 sec)mysql> insert into test4 values ('1992-03-08 11:11:11'),(19920308111111),('19920308111111'),(20101231080808);
Query OK, 4 rows affected (0.10 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> select * from test4;
+---------------------+
| id |
+---------------------+
| 1992-03-08 11:11:11 |
| 1992-03-08 11:11:11 |
| 1992-03-08 11:11:11 |
| 2010-12-31 08:08:08 |
+---------------------+
4 rows in set (0.00 sec)mysql> truncate table test4;
Query OK, 0 rows affected (0.19 sec)
mysql> insert into test4 values (920308111111),('92-03-08 11:11:11');
Query OK, 2 rows affected (0.11 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> select * from test4;
+---------------------+
| id |
+---------------------+
| 1992-03-08 11:11:11 |
| 1992-03-08 11:11:11 |
+---------------------+
2 rows in set (0.00 sec)五、TIMESTAMP
TIMESTAMP类型和DATETIME类型的表示格式相同，存储4个字节（比DATETIME少），取值范围少于DATETIME类型。TIMESTAMP和DATETIME最大不同于：TIMESTAMP根据时区显示时间。如果不明白可以看下面的例子：
mysql> create table test5 (id timestamp);
Query OK, 0 rows affected (0.27 sec)
mysql> desc test5;
+-------+-----------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+-------+-----------+------+-----+-------------------+-----------------------------+
| id | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+-------+-----------+------+-----+-------------------+-----------------------------+
1 row in set (0.01 sec)
mysql> insert into test5 values (NOW());
Query OK, 1 row affected (0.06 sec)
mysql> select * from test5;
+---------------------+
| id |
+---------------------+
| 2018-03-28 13:16:09 |
+---------------------+
1 row in set (0.00 sec)
#设置为东十区，比东八区快两个小时。
mysql> set time_zone='+10:00';
Query OK, 0 rows affected (0.00 sec)
mysql> select * from test5;
+---------------------+
| id |
+---------------------+
| 2018-03-28 15:16:09 |
+---------------------+
1 row in set (0.00 sec)