删除 MySQL 中 5 天前的数据
若要删除所有 5 天前的数据,则可以使用以下语法 -
delete from yourTableName where datediff(now(), yourTableName.yourDateColumnName) > 5;
注意: - 假设当前日期是 2019-03-10。
为理解此概念,让我们创建一个表。创建表的查询如下 -
mysql> create table deleteRowsOlderThan5Demo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Name varchar(100), -> Post_Date date -> ); Query OK, 0 rows affected (0.69 sec)
对表中插入一些记录。查询如下 -
mysql> insert into deleteRowsOlderThan5Demo(Name,Post_Date) values('Larry','2019-03- 11'); Query OK, 1 row affected (0.12 sec) mysql> insert into deleteRowsOlderThan5Demo(Name,Post_Date) values('Mike','2019-02- 12'); Query OK, 1 row affected (0.17 sec) mysql> insert into deleteRowsOlderThan5Demo(Name,Post_Date) values('Sam','2019-03- 10'); Query OK, 1 row affected (0.12 sec) mysql> insert into deleteRowsOlderThan5Demo(Name,Post_Date) values('Carol','2019-03- 01'); Query OK, 1 row affected (0.23 sec) mysql> insert into deleteRowsOlderThan5Demo(Name,Post_Date) values('David','2019-01- 31'); Query OK, 1 row affected (0.19 sec) mysql> insert into deleteRowsOlderThan5Demo(Name,Post_Date) values('Maxwell','2019-01- 26'); Query OK, 1 row affected (0.10 sec) mysql> insert into deleteRowsOlderThan5Demo(Name,Post_Date) values('John','2019-02- 19'); Query OK, 1 row affected (0.12 sec)
对表中所有记录进行显示。查询如下 -
mysql> select *from deleteRowsOlderThan5Demo;
输出如下 -
+----+---------+------------+ | Id | Name | Post_Date | +----+---------+------------+ | 1 | Larry | 2019-03-11 | | 2 | Mike | 2019-02-12 | | 3 | Sam | 2019-03-10 | | 4 | Carol | 2019-03-01 | | 5 | David | 2019-01-31 | | 6 | Maxwell | 2019-01-26 | | 7 | John | 2019-02-19 | +----+---------+------------+ 7 rows in set (0.00 sec)
删除所有 5 天前数据命令如下 -
mysql> delete from deleteRowsOlderThan5Demo -> where datediff(now(), deleteRowsOlderThan5Demo.Post_Date) > 5; Query OK, 5 rows affected (0.14 sec)
我们再次查看表记录。查询如下 -
mysql> select *from deleteRowsOlderThan5Demo;
输出如下 -
+----+-------+------------+ | Id | Name | Post_Date | +----+-------+------------+ | 1 | Larry | 2019-03-11 | | 3 | Sam | 2019-03-10 | +----+-------+------------+ 2 rows in set (0.00 sec)
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