What is the best way to check if an object exists in the database from a performance point of view? I'm using Entity Framework 1.0 (ASP.NET 3.5 SP1).
If you don't want to execute SQL directly, the best way is to use Any(). This is because Any() will return as soon as it finds a match. Another option is Count(), but this might need to check every row before returning.
Here's an example of how to use it:
if (context.MyEntity.Any(o => o.Id == idToMatch))
{
// Match!
}
And in vb.net
If context.MyEntity.Any(function(o) o.Id = idToMatch) Then
' Match!
End If