MySQL查询从不同的列但相似的行计算两个日期之间的天数

让我们首先创建一个表-

create table DemoTable1471 -> ( -> EmployeeJoiningDate date, -> EmployeeRelievingDate date -> );

使用插入命令在表中插入一些记录-

insert into DemoTable1471 values(2018-06-21,2018-12-21); insert into DemoTable1471 values(2017-01-19,2019-01-31); insert into DemoTable1471 values(2015-12-31,2016-03-01);

使用select语句显示表中的所有记录-

select * from DemoTable1471;

这将产生以下输出-

+---------------------+-----------------------+ | EmployeeJoiningDate | EmployeeRelievingDate | +---------------------+-----------------------+ | 2018-06-21 | 2018-12-21 | | 2017-01-19 | 2019-01-31 | | 2015-12-31 | 2016-03-01 | +---------------------+-----------------------+ 3 rows in set (0.00 sec)

这是计算两个日期之间的天的查询-

select datediff(EmployeeRelievingDate,EmployeeJoiningDate) as EmployeeWorkDays from DemoTable1471;

这将产生以下输出-

+------------------+ | EmployeeWorkDays | +------------------+ | 183 | | 742 | | 61 | +------------------+ 3 rows in set (0.00 sec)