Mysql 如何在定期更新数据的过程中获得不大于给定日期范围的准确数据

我有一个数据库，有一些单位定期报告。我想要一个查询，在那里我可以看到在某个日期之后没有登录的单位

select distinct FSS_LIVE_50.dbo.AgencyVehicle.AgencyVehicleName from FSS_LIVE_50.dbo.AgencyVehicle
inner join FSS_LIVE_50.dbo.VehicleLocation
on FSS_LIVE_50.dbo.AgencyVehicle.AgencyVehicleKey = FSS_LIVE_50.dbo.VehicleLocation.AgencyVehicleKey
where FSS_LIVE_50.dbo.VehicleLocation.GPSLocationDate < '2013-01-01'
and FSS_LIVE_50.dbo.AgencyVehicle.TermDate is NULL
order by AgencyVehicleName

现在它向我展示了2013-01-01之后也有日志的车辆，因为它们在该日期之前和之后都有日志

如何从显示中排除在此之后还有日期日志的名称>？

将distinct更改为group by。然后添加having子句。您正在寻找截止日期之前的最大日期：

select FSS_LIVE_50.dbo.AgencyVehicle.AgencyVehicleName
from FSS_LIVE_50.dbo.AgencyVehicle inner join
     FSS_LIVE_50.dbo.VehicleLocation
     on FSS_LIVE_50.dbo.AgencyVehicle.AgencyVehicleKey = FSS_LIVE_50.dbo.VehicleLocation.AgencyVehicleKey
where FSS_LIVE_50.dbo.AgencyVehicle.TermDate is NULL
group by FSS_LIVE_50.dbo.AgencyVehicle.AgencyVehicleName
having MAX(FSS_LIVE_50.dbo.VehicleLocation.GPSLocationDate) < '2013-01-01'
order by AgencyVehicleName;

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明智地使用别名也会使您的查询更具可读性。

请更正大写文本-使用正确的大小写。