Bind Linq to Datagridtextcolumn

Question

I would like to add values to my DatagridTextcolumn from a Linq query.

What I have tried:

DataGridTextColumn test = new DataGridTextColumn();
test.Binding = new Binding("test");
dgServer.Columns.Add(test);

dgServer.Items.Add(new Person()
{
  Status = Convert.ToBoolean(from a in db.Persons
          from d in db.PersonDetails
          where a.pID == d.pDID && a.State == "Active" 
          select a)
});

XAML

<DataGridTextColumn x:Name="test" Binding="{Binding}" Header="test"/>

I have an exception for the above code, saying

Unable to cast object of type 'System.Data.Objects.ObjectQuery`1 to type 'System.IConvertible'.

how to bind to a DatagridTextcolumn binding from LINQ to SQL.

Kindly Help

Answer 1

This is problematic code -

Status = Convert.ToBoolean(from a in db.Persons
          from d in db.PersonDetails
          where a.pID == d.pDID && a.State == "Active" 
          select a)

The query inside will return IEnumerable of type Person and you are trying to convert this to Boolean which obviously won't compile since there is no implicit conversion from IEnumerable<Person> to Boolean .

Answer 2

The problem is that your are trying to convert a linq query rather than the results of that query. The issue arises from Linq's deferred execution model. Try adding a 'FirstOrDefault()' method to the parameter of your ToBoolean call:

Status = Convert.ToBoolean((from a in db.Persons
      from d in db.PersonDetails
      where a.pID == d.pDID && a.State == "Active" 
      select a).FirstOrDefault())

Rohit also has a good point - you need to make sure than you can actually convert from type Person to Boolean