Entity Framework generating LEFT OUTER JOINs when it should be doing INNER JOINs (multiple tables)
c#, entity-framework, linq
Solution
Answer was: Bug in entity framework. Download very latest version and they are all inner joins.
Problem
I have the following weird behaviour: ``` public class Result { [Key] public int Id { get; set; } public int RuleId { get; set; } public int UserId { get; set; } [ForeignKey("RuleId")] public virtual Rule Rule { get; set; } [ForeignKey("UserId ")] public virtual User User { get; set; } } public class Rule { [Key] public int Id { get; set; } public string Name { get; set; } // More columns } public class User { [Key] public int Id { get; set; } public string Name { get; set; } // More columns } ``` If I do: ``` ctx.Results.AsQueryable().Select(r => new { r.Rule.Name } ).ToList(); ``` The query executed in SQL Server does an inner join on Rule: ``` SELECT [Extent1].[RuleId] AS [RuleId], [Extent2].[Name] AS [Name] FROM [dbo].[result] AS [Extent1] INNER JOIN [dbo].[rule] AS [Extent2] ON [Extent1].[RuleId] = [Extent2].[Id] ``` BUT if I do: ``` ctx.Results.AsQueryable().Select(r => new { rn = r.Rule.Name, un = r.User.Name } ).ToList(); ``` The query executed does an inner join on rule but an OUTER JOIN on User. ``` SELECT [Extent1].[UserId] AS [UserId], [Extent2].[Name] AS [Name], [Extent3].[Name] AS [Name1] FROM [dbo].[result] AS [Extent1] INNER JOIN [dbo].[rule] AS [Extent2] ON [Extent1].[RuleId] = [Extent2].[Id] LEFT OUTER JOIN [dbo].[user] AS [Extent3] ON [Extent1].[UserId] = [Extent3].[Id] ``` Surely this is wrong?