EF -> SQL

-- LINQ expression
var allSchools =
    Context.Schools.
    Include("District.State").
        Where(s => s.Nces == "" || s.Nces == null).ToList();


-- result
SELECT
    [Extent1].[id] AS [id],
    [Extent1].[nces] AS [nces],
    [Extent1].[name] AS [name],
    [Extent1].[district_id] AS [district_id],
    [Extent2].[id] AS [id1],
    [Extent2].[name] AS [name1],
    [Extent2].[state_id] AS [state_id],
    [Extent3].[fips] AS [fips],
    [Extent3].[abbr] AS [abbr],
    [Extent3].[name] AS [name2]
FROM
    [dbo].[Schools] AS [Extent1]
    LEFT OUTER JOIN [dbo].[Districts] AS [Extent2]
        ON [Extent1].[district_id] = [Extent2].[id]
    LEFT OUTER JOIN [dbo].[States] AS [Extent3]
        ON [Extent2].[state_id] = [Extent3].[fips]
WHERE
    [Extent1].[nces] = N''
    OR [Extent1].[nces] IS NULL