显示无法创建类型“”的常量值。 在这种情况下，仅支持基本类型（例如Int32，String和Guid）

Question

I am quering the some tables to get the list of employees based on some conditions using the linq. as

Here class " EmpJobPosition " is from Model.

List<int> empjList=ObjToList(employeeJobPositionIds);

List<EmpJobPosition> empJobPositionList =
     (from i in ctx.EmpJobPositions
      where empjList.Contains(i.EmpJobPositionId)
      select i).ToList<EmpJobPosition>();

var query = (from emp in ctx.Employees
     join resg in ctx.Resignations on emp.EmployeeID equals resg.EmployeeID into resglist
     from resg in resglist.DefaultIfEmpty()
     join jpos in empJobPositionList
         on emp.EmployeeID equals jpos.EmployeeId into jposList
     from jpos in jposList.DefaultIfEmpty()
         (resg == null || resg.HasLeft == false) && emp.CompanyID == 1
     select new EmployeesViewModel()).ToList();

But Here while join with empJobPositionList it is showig error like

{"Unable to create a constant value of type 'Etisbew.eOffice.EFModel.EntityModel.EmpJobPosition'. Only primitive types ('such as Int32, String, and Guid') are supported in this context."}

What is the problem here.

Answer 1

You could do something like that (don't try to join an IQueryable on an List)

var query = (
     from emp in ctx.Employees
     join resg in ctx.Resignations 
              on emp.EmployeeID equals resg.EmployeeID into resglist
     from leftresg in resglist.DefaultIfEmpty()

     //put the where clause on EmpJobPositions here
     join jpos in ctx.EmpJobPositions.Where(x => empjList.Contains(x.EmpJobPositionId))
              on emp.EmployeeID equals jpos.EmployeeId into jposList
     from leftjpos in jposList.DefaultIfEmpty()
         //don't understand this line, are you missing a where ?
         //(leftresg == null || leftresg.HasLeft == false) && emp.CompanyID == 1
     select new EmployeesViewModel()).ToList();