如何在 MySQL 中将 DATETIME 转换为 DATE?
mysqlmysqli database
要在 MySQL 中将 DATETIME 转换为 DATE，请使用 CAST() 函数。语法如下 −
select cast(yourColumnName as Date) as anyVariableName from yourTableName;
为了理解上述语法，让我们首先创建一个表 −
mysql> create table ConvertDatetimeToDate −> ( −> YourDatetime datetime −> ); Query OK, 0 rows affected (0.95 sec)
使用 insert 命令将 datetime 插入表中。查询如下 −
mysql> insert into ConvertDatetimeToDate values(date_add(now(),interval 1 day)); Query OK, 1 row affected (0.17 sec) mysql> insert into ConvertDatetimeToDate values(date_add(now(),interval -1 day)); Query OK, 1 row affected (0.15 sec) mysql> insert into ConvertDatetimeToDate values(date_add(now(),interval 1 year)); Query OK, 1 row affected (0.10 sec) mysql> insert into ConvertDatetimeToDate values(date_add(now(),interval -1 year)); Query OK, 1 row affected (0.16 sec)
显示上面插入的所有记录，查询如下 −
mysql> select *from ConvertDatetimeToDate;
以下是输出 −
+---------------------+ | YourDatetime | +---------------------+ | 2018-11-28 16:12:50 | | 2018-11-26 16:13:00 | | 2019-11-27 16:13:13 | | 2017-11-27 16:13:24 | +---------------------+ 4 rows in set (0.00 sec)
现在您可以应用上述语法将 datetime 转换为 date。查询如下 −
mysql> select cast(YourDatetime as Date) as OnlyDateDemo from ConvertDatetimeToDate;
以下是输出 −
+--------------+ | OnlyDateDemo | +--------------+ | 2018-11-28 | | 2018-11-26 | | 2019-11-27 | | 2017-11-27 | +--------------+ 4 rows in set (0.00 sec)
