如何从不同的 MySQL 列合并日期和时间,以便与整个 DateTime 进行比较?
你可以使用 CONCAT() 函数将日期和时间从不同的 MySQL 列中组合起来,以便与整个日期时间进行比较。语法如下 −
SELECT *FROM yourTableName WHERE CONCAT(yourDateColumnName,'',yourTimeColumnName) > 'yourDateTimeValue';
为了理解上述语法,我们创建一个表。创建表的查询如下 −
mysql> create table DifferentDateTime -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> ArrivalDate date, -> ArrivalTime time -> ); Query OK, 0 rows affected (1.53 sec)
使用 insert 命令在表中插入一些记录。查询如下 −
mysql> insert into DifferentDateTime(ArrivalDate,ArrivalTime) values(curdate(),'10:27:30'); Query OK, 1 row affected (0.14 sec) mysql> insert into DifferentDateTime(ArrivalDate,ArrivalTime) values('2016-04-24','15:00:00'); Query OK, 1 row affected (0.18 sec) mysql> insert into DifferentDateTime(ArrivalDate,ArrivalTime) values('2015-12-25','12:30:30'); Query OK, 1 row affected (0.18 sec) mysql> insert into DifferentDateTime(ArrivalDate,ArrivalTime) values('2012-01-31','16:00:30'); Query OK, 1 row affected (0.11 sec) mysql> insert into DifferentDateTime(ArrivalDate,ArrivalTime) values('2000-07-12','09:45:31'); Query OK, 1 row affected (0.11 sec)
示例
使用 select 语句从表中显示所有记录。查询如下 −
mysql> select *from DifferentDateTime;
输出
+----+-------------+-------------+ | Id | ArrivalDate | ArrivalTime | +----+-------------+-------------+ | 1 | 2019-02-14 | 10:27:30 | | 2 | 2016-04-24 | 15:00:00 | | 3 | 2015-12-25 | 12:30:30 | | 4 | 2012-01-31 | 16:00:30 | | 5 | 2000-07-12 | 09:45:31 | +----+-------------+-------------+ 5 rows in set (0.00 sec)
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示例
以下是将日期和时间从不同的列中组合起来并与日期时间值进行比较的查询 −
mysql> select *from DifferentDateTime where concat(ArrivalDate,'',ArrivalTime) > '2007-01-31 12:30:30';
输出
+----+-------------+-------------+ | Id | ArrivalDate | ArrivalTime | +----+-------------+-------------+ | 1 | 2019-02-14 | 10:27:30 | | 2 | 2016-04-24 | 15:00:00 | | 3 | 2015-12-25 | 12:30:30 | | 4 | 2012-01-31 | 16:00:30 | +----+-------------+-------------+ 4 rows in set (0.00 sec)
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