MYSQL函数 小记：DATEDIFF,TIMESTAMPDIFF,DATE_SUB

• DATEDIFF 计算日期差
  –注：返回值是相差的天数，不能定位到小时、分钟和秒

mysql> select DATEDIFF(A.modtime,NOW()),A.* from SYS_AREA A;
+---------------------------+--------+---------+------------+---------+---------+---------------------+
| DATEDIFF(A.modtime,NOW()) | AREAID | PAREAID | AREAPY     | ORDERID | ISAPPLY | MODTIME             |
+---------------------------+--------+---------+------------+---------+---------+---------------------+
|                     -2739 | 0      | NULL    | top        | 0       | 1       | 2012/7/4            |
|                     -2171 | 330000 | 0       | zhejiang   | 5       | 1       | 2014/1/23           |
|                       -79 | 330100 | 330000  | hangzhou   | 99      | 1       | 2019/10/16 10:53:55 |
|                      -697 | 330102 | 330100  | sahgncheng | 1       | 1       | 2018/2/5            |
|                      -697 | 330103 | 330100  | xiacheng   | 2       | 1       | 2018/2/5            |
|                      -697 | 330104 | 330100  | jianggan   | 3       | 1       | 2018/2/5            |
|                       -80 | 330106 | 330100  | xihu       | 5       | 1       | 2019/10/15 8:46:42  |
|                       -80 | 330108 | 330100  | binjiang   | 6       | 1       | 2019/10/15 8:47:21  |
|                       -80 | 330184 | 330100  | yuhang     | 11      | 1       | 2019/10/15 8:57:27  |
|                       -80 | 330181 | 330100  | xiaoshan   | 10      | 1       | 2019/10/15 8:57:02  |
|                       -80 | 330187 | 330100  | fuyang     | 12      | 1       | 2019/10/15 8:57:41  |
|                       -80 | 330105 | 330100  | gongshu    | 4       | 1       | 2019/10/15 8:46:34  |
|                       -80 | 330110 | 330100  | zhijiang   | 9       | 1       | 2019/10/15 8:56:50  |
|                       -80 | 330186 | 330100  | xiasha     | 7       | 1       | 2019/10/15 8:47:37  |
|                       -80 | 330188 | 330100  | tonglu     | 14      | 1       | 2019/10/15 8:58:11  |
|                       -80 | 330189 | 330100  | jiande     | 16      | 1       | 2019/10/15 8:58:42  |
|                       -80 | 330190 | 330100  | chunan     | 15      | 1       | 2019/10/15 8:58:27  |
|                        -1 | 330191 | 330100  | linan      | 13      | 1       | 2020-01-02 11:36:31 |
|                         0 | 330231 | 330100  | dajiangdo  | 8       | 1       | 2020-01-03 11:29:35 |
+---------------------------+--------+---------+------------+---------+---------+---------------------+
19 rows in set (0.00 sec)

• TIMESTAMPDIFF
  – 可以精确到天（DAY）、小时（HOUR），分钟（MINUTE）和秒（SECOND）

mysql> select A.modtime,now(),DATEDIFF(A.modtime,NOW()),TIMESTAMPDIFF(DAY,A.modtime,NOW()) DAY,TIMESTAMPDIFF(HOUR,A.modtime,NOW()) HOUR ,TIMESTAMPDIFF(MINUTE,A.modtime,NA;
+---------------------+---------------------+---------------------------+------+-------+---------+-----------+
| modtime             | now()               | DATEDIFF(A.modtime,NOW()) | DAY  | HOUR  | MINUTE  | SECOND    |
+---------------------+---------------------+---------------------------+------+-------+---------+-----------+
| 2012/7/4            | 2020-01-03 11:44:33 |                     -2739 | 2739 | 65747 | 3944864 | 236691873 |
| 2014/1/23           | 2020-01-03 11:44:33 |                     -2171 | 2171 | 52115 | 3126944 | 187616673 |
| 2019/10/16 10:53:55 | 2020-01-03 11:44:33 |                       -79 |   79 |  1896 |  113810 |   6828638 |
| 2018/2/5            | 2020-01-03 11:44:33 |                      -697 |  697 | 16739 | 1004384 |  60263073 |
| 2018/2/5            | 2020-01-03 11:44:33 |                      -697 |  697 | 16739 | 1004384 |  60263073 |
| 2018/2/5            | 2020-01-03 11:44:33 |                      -697 |  697 | 16739 | 1004384 |  60263073 |
| 2019/10/15 8:46:42  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115377 |   6922671 |
| 2019/10/15 8:47:21  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115377 |   6922632 |
| 2019/10/15 8:57:27  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115367 |   6922026 |
| 2019/10/15 8:57:02  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115367 |   6922051 |
| 2019/10/15 8:57:41  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115366 |   6922012 |
| 2019/10/15 8:46:34  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115377 |   6922679 |
| 2019/10/15 8:56:50  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115367 |   6922063 |
| 2019/10/15 8:47:37  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115376 |   6922616 |
| 2019/10/15 8:58:11  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115366 |   6921982 |
| 2019/10/15 8:58:42  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115365 |   6921951 |
| 2019/10/15 8:58:27  | 2020-01-03 11:44:33 |                       -80 |   80 |  1922 |  115366 |   6921966 |
| 2020-01-02 11:36:31 | 2020-01-03 11:44:33 |                        -1 |    1 |    24 |    1448 |     86882 |
| 2020-01-03 11:29:35 | 2020-01-03 11:44:33 |                         0 |    0 |     0 |      14 |       898 |
+---------------------+---------------------+---------------------------+------+-------+---------+-----------+
19 rows in set (0.00 sec)

• date_sub 加减时间

mysql> select date_sub(now(),interval 1 day) 减,date_sub(now(),interval 0 day),date_sub(now(),interval -1 day) 加;
+---------------------+--------------------------------+---------------------+
| 减                  | date_sub(now(),interval 0 day) | 加                  |
+---------------------+--------------------------------+---------------------+
| 2020-01-02 11:35:49 | 2020-01-03 11:35:49            | 2020-01-04 11:35:49 |
+---------------------+--------------------------------+---------------------+
1 row in set (0.00 sec)