如何解决LINQ中的where子句子查询
我正在尝试将SQL语法转换为LINQ查询,而子查询却有问题。 我想选择一个表中的Id的最大日期时间作为另一个选择命令的子查询,但是我不知道下面的代码是对是错。 我在Sql中拥有的
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
final WindowInsetsController insetsController =getWindow().getInsetsController();
if(insetsController!=null){
insetsController.hide(WindowInsets.Type.statusBars());
}else
{
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
}
}
我在linq中尝试过的东西
select ap.*,aph.Lat as 'personLat',aph.Lng as 'personLng',l.cityId,l.Lat as 'LifecenterLat',l.lng as 'LifecenterLng',l.Id as 'LifeCenterId'
from Applicant ap
inner join ApplicantAddressHistory aph on ap.Id = aph.ApplicantId
inner join LifePlusCenter l on aph.CityId = l.CityId
Where ap.FamilyRoleTypeId = '82e26080-fda6-4396-946c-40d0e267f1f3' and aph.CreatedDate in (select max(CreatedDate) from ApplicantAddressHistory
where ApplicantAddressHistory.ApplicantId = ap.Id)
order by ap.NationalityCode
没有下面的代码行,我的linq可以正常工作。
var innerJoinMultipleTables = from app in db.Applicant.Where(x => x.FamilyRoleTypeId == Guid.Parse("82e26080-fda6-4396-946c-40d0e267f1f3"))
join aph in db.ApplicantAddressHistory on app.Id equals aph.ApplicantId
where aph.CreatedDate == db.ApplicantAddressHistory.Max(x => x.CreatedDate && x.Id=aph.Id)
join l in db.LifePlusCenter on aph.CityId equals l.CityId
let centerLat = l.Lat
let centerLng = l.Lng
orderby app.NationalityCode
select new { app,aph.Lat,aph.Lng,l.CityId,l.Branch,centerLat,centerLng };
我需要在Linq中的以下代码中将其作为子查询
where aph.CreatedDate == db.ApplicantAddressHistory.Max(x => x.CreatedDate && x.Id=aph.Id)
我终于尝试了此方法,它仍然有效,但是不知道它的正确方法吗?!
select max(CreatedDate) from ApplicantAddressHistory where ApplicantAddressHistory.ApplicantId = '9836CEC4-EDCB-492C-9899-DF4279210CD2'
解决方法
不知道它在Linq中如何工作,但是您可以按如下所示修改查询,以获取每个ApplicantId的CreatedDate的最新详细信息。
select ap.*,aph.Lat as 'personLat',aph.Lng as 'personLng',l.cityId,l.Lat as 'LifecenterLat',l.lng as 'LifecenterLng',l.Id as 'LifeCenterId'
from Applicant ap
inner join
(select *
from
(select *,row_number() over(partition by ApplicantId order by CreatedDate desc) rw
from ApplicantAddressHistory
) p
where p.rw=1
) aph
on ap.Id = aph.ApplicantId
inner join LifePlusCenter l
on aph.CityId = l.CityId
Where ap.FamilyRoleTypeId = '82e26080-fda6-4396-946c-40d0e267f1f3'
/*
and aph.CreatedDate in (
select max(CreatedDate) from ApplicantAddressHistory
where ApplicantAddressHistory.ApplicantId = ap.Id
)
*/
order by ap.NationalityCode
,
最后我来到了:
var z = from app in db.Applicant
join aph in db.ApplicantAddressHistory on app.Id equals aph.ApplicantId
join l in db.LifePlusCenter on aph.CityId equals l.CityId
let createDate = app.ApplicantAddressHistory.Max(c => c.CreatedDate)
where createDate.HasValue && aph.CreatedDate == createDate
&& app.FamilyRoleTypeId == Guid.Parse("82e26080-fda6-4396-946c-40d0e267f1f3")
let personLat = aph.Lat
let personLng = aph.Lng
let centerId = l.Id
let LifecenterLat = l.Lat
let LifecenterLng = l.Lng
orderby app.NationalityCode
select new { app,aph,l,app.Id,l.CityId,centerId,personLat,personLng,LifecenterLat,LifecenterLng };
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。