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c#linqentity-frameworklinq-to-entities

Proper way to delete record in LINQ to Entities


I just have a very simple situation where all I need is to delete record using Linq2Entities. I tried to do some research and still can't figure out the right way to do it.

Here's my simple code:

[DataObjectMethod(DataObjectMethodType.Delete)]
public void DeleteEmployee(Employee z)
{
    using (var ctx = new MyEntity())
    {
        var x = (from y in ctx.Employees
                 where  y.EmployeeId == z.EmployeeId
                 select y).FirstOrDefault();
         ctx.DeleteObject(x);
         ctx.SaveChanges();
    }
 }

[DataObjectMethod(DataObjectMethodType.Select)]
public List<Employee> GetAllEmployee()
{
    using (var ctx = new MyEntity())
    {
        var x = from y in ctx.Employees
                select y;
        return x.ToList();
    }
}

I can delete a particular record if for example I assign y.EmployeeName == "Harold Javier" to the Delete method above, but when I assign y.EmployeeId == z.EmployeeId to the above code, the delete doesn't work. (Note: EmployeeId is the primary key of the Employee table)


Solution

  • I decided to answer my own question.

    My delete function worked when I did the following:

    using (var ctx = new MyEntity())
        {
            var x = (from y in ctx.Employees
                 orderby  y.EmployeeId descending
                 select y).FirstOrDefault();
            ctx.Employees.DeleteObject(x);
            ctx.SaveChanges();
        }
    

    I know there could be a better approach than this, but it works for me for the mean time.