C# linq Expression left join如何使用

eg：
注意：on 前后要保持字段名一致

var bleftQuery = from f in bFamiliesjoin a in bAudits on new{Id=f.Id,DCYId=f.ModifyID} equals new{Id=a.HealthFamilyId,a.DCYId} into nafrom a in na.DefaultIfEmpty()select new FamilyWithAudit(){Id = f.Id,SearchCode = f.SearchCode,FamilyName = f.FamilyName,MemberCount = f.MemberCount,FamilyCode = f.FamilyCode,NeighborhoodCommitteeCode = f.NeighborhoodCommitteeCode,Address = f.Address,IsAbandoned = f.IsAbandoned,KpOrganizationLeaderId = f.KpOrganizationLeaderId,KISH = f.KISH,IntervieweeCode = f.IntervieweeCode,IntervieweeMobile = f.IntervieweeMobile,IntervieweeMobileRelationship = f.IntervieweeMobileRelationship,IntervieweeCodeSignature = f.IntervieweeCodeSignature,Province = f.Province,City = f.City,County = f.County,Town = f.Town,Village = f.Village,AreaCode = f.AreaCode,InvestigateState = f.InvestigateState,JianCeCode = f.JianCeCode,StreetCode = f.StreetCode,SampleNum = f.SampleNum,SampleType = f.SampleType,NeedRecord = f.NeedRecord,NeedPhotot = f.NeedPhotot,AuditFailedNeedHandle = f.AuditFailedNeedHandle,AnswerCostTime = f.AnswerCostTime,SetRange = f.SetRange,Remark = f.Remark,CreateID = f.CreateID,CreateTime = f.CreateTime,ModifyID = f.ModifyID,ModifyTime = f.ModifyTime,DeletedTime = f.DeletedTime,KpExamVersionId = f.KpExamVersionId,IsHandle = f.IsHandle,IsNoOne = f.IsNoOne,AuditResult = a != null ? a.AuditResult : AuditResult.未调查_添加或者导入};var bListAll = bleftQuery.ToList();
//一般的联表查询
var bListResult = bList.Join(_context.FamilyAudioSub.Select(r => new {AudioId = r.AudioId}), f => f.Id, r => r.AudioId,(f, r) => new FamilyAudio(){Id = f.Id,CreateID = f.CreateID,CreateTime = f.CreateTime,Duration = f.Duration,FamilyId = f.FamilyId,Type = f.Type,Size = f.Size}).ToList();

C# linq Expression left join如何使用相关推荐

“Mvc.ExceptionHandling.AbpExceptionFilter – Processing of the LINQ expression ‘xxx’ by ‘NavigationEx
本文由比特飞原创发布,欢迎大家踊跃转载. 转载请注明本文地址:"Mvc.ExceptionHandling.AbpExceptionFilter – Processing of the ...
LINQ：使用join进行联接
在LINQ中,join可以实现3种类型的联接,分别是内部联接.分组联接.左外部联接. 内部联接: private static void UseInnnerJoin(){int[] intArray1 ...
LINQ系列：LINQ to SQL Join连接
1. 一对多 var expr = context.Products.Where(p => p.Category.CategoryName == "LINQ to SQL" ...
C# Linq中的Join使用
1.使用两个数据表Dk_SyDlCxInfo和testTable,当然多个也行,只不过需要使用多个Join,表大家随意建就是了,可以通过一个字段对两个表进行连接,而我使用两个字段来确定唯一性 2.使用 ...
LINQ体验(6)——LINQ语句之Join和Order By
Join操作适用场景:在我们表关系中有一对一关系,一对多关系,多对多关系等.对各个表之间的关系,就用这些实现对多个表的操作. 说明:在Join操作中,分别为Join(Join查询), SelectM ...
Linq 三表 left join 的实现
目的实现: select id,name,jname,cname from userinfo u left join job j on u.job=j.jid left join city c on ...
Linq 多表连接查询join
在查询语言中,通常需要使用联接操作.在 LINQ 中,可以通过 join 子句实现联接操作.join 子句可以将来自不同源序列,并且在对象模型中没有直接关系(数据库表之间没有关系)的元素相关联,唯一的 ...
DataRow.Field Expression [DataTable动态linq]
我们一般在学习Linq查询时,查询条件都是写死的.但是我们在实际使用过程中肯定不能这样,而是需要动态创建Linq查询条件,这里我们就需要用到Linq.Expression,用Expression来创建 ...
Linq to SQL 资源
Scott Guthrie 的 Linq to SQL 系列: 1)介绍 http://weblogs.asp.net/scottgu/archive/2007/05/19/using-linq-to ...

C# linq Expression left join如何使用

C# linq Expression left join如何使用相关推荐

最新文章

热门文章