MySQL 查詢僅更新日期中的月份?
要僅更新日期中的月份,請使用 MONTH()。我們首先建立一個表 -
mysql> create table DemoTable861(AdmissionDate date); Query OK, 0 rows affected (1.22 sec)
使用插入命令在表中插入一些記錄 -
mysql> insert into DemoTable861 values('2019-01-21'); Query OK, 1 row affected (0.31 sec) mysql> insert into DemoTable861 values('2018-01-01'); Query OK, 1 row affected (0.49 sec) mysql> insert into DemoTable861 values('2016-01-02'); Query OK, 1 row affected (1.27 sec) mysql> insert into DemoTable861 values('2018-01-14'); Query OK, 1 row affected (0.47 sec)
使用選擇語句從表中顯示所有記錄 -
mysql> select *from DemoTable861;
這將產生以下輸出 -
+---------------+ | AdmissionDate | +---------------+ | 2019-01-21 | | 2018-01-01 | | 2016-01-02 | | 2018-01-14 | +---------------+ 4 rows in set (0.00 sec)
以下是僅更新月份的查詢 -
mysql> update DemoTable861 set AdmissionDate=date_add(AdmissionDate,Interval -1 month) where month(AdmissionDate)=01; Query OK, 4 rows affected (0.42 sec) Rows matched : 4 Changed : 4 Warnings : 0
讓我們再次檢查一下表記錄 -
mysql> select *from DemoTable861;
這將產生以下輸出 -
+---------------+ | AdmissionDate | +---------------+ | 2018-12-21 | | 2017-12-01 | | 2015-12-02 | | 2017-12-14 | +---------------+ 4 rows in set (0.00 sec)
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