LINQ Object Persistance

Question

Using the following code here

Sub FooSub
Dim db As New FooDataContext
Dim u = From p In db.FooTable Where p.FooColumn = FooData Select p

Do Stuff
End Sub

Do I have to manually create a class to map the data from my FooTable if I want it to persist in the application? If I declare u as a class-wide variable, then once SubFoo ends, I can no longer access the data in u

Answer 1

Actually, u will only be IQueryable<typeof(p)>. The database won't even be hit until you try to iterate over that collection.

If you want some objects to work with after the DataContext connection has closed, you'll want to call u.ToList before you close the connection to get a list of the results.

From there, you can change the objects themselves as you like. If you want changes to persist back to the database, call db.SubmitChanges