如何将EF多表查询返回的list类型结果改写成长尾词？

本文共计223个文字，预计阅读时间需要1分钟。

代码示例如下：List list=fromaindb.TestData join bindb.TestObject on a.object_id equals b.object_id join Organization1 indb.Organization on a.org_id equals Organization1.org_id select new RailwayProject.Entities.DataAnalysis();

代码是这样的ListRailwayProject.Entities.DataAnalyzelistfromaindb.TestData 代码是这样的Listlist=fromaindb.TestData joinbindb.TestObjectona.object_idequalsb.object_id joinOrganization1indb.Organizationona.org_idequalsOrganization1.OrgId joinOrganization2indb.OrganizationonOrganization1.ParentIdequalsOrganization2.org_id joinOrganization3indb.OrganizationonOrganization2.ParentIdequalsOrganization3.org_id joinOrganization4indb.OrganizationonOrganization3.ParentIdequalsOrganization4.org_id joinindexResultindb.IndexResultona.data_idequalsindexResult.data_id selectnewRailwayProject.Entities.DataAnalyze { a.data_id }; 然后提示错误 1 无法使用集合初始值初始化类型“RailwayProject.Entities.DataAnalyze”，原因是它未实现“System.Collections.IEnumerable” 这样的错误，不知道怎么转...

4 个解决方案

#1

ToList()一下。

#2

Listlist=fromaindb.TestData 前面这段改成 varlist=fromaindb.TestData 后面改成 selectnew { a.data_id }; 然后用list.tolist()一下

#3

2楼正解，ToList后才会查询。

#4

publicclassDataAnalyze{publicintOrgId{get;set;}//取出你的想要的字段或者怎么处理}Listlist=(fromaindb.TestDataselectnewRailwayProject.Entities.DataAnalyze{OrgId=a.org_id,ParentId=a.ParentId//依次往下写。}).ToList();