Best way to check if object exists in Entity Framework?

Question

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).

Answer 1

From a performance point of view, I guess that a direct SQL query using the EXISTS command would be appropriate. See here for how to execute SQL directly in Entity Framework: http://blogs.microsoft.co.il/blogs/gilf/archive/2009/11/25/execute-t-sql-statements-in-entity-framework-4.aspx

Answer 2

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!
}