Comments on: LINQ To SQL Join On Multiple Conditions

By: Deepak

Deepak — Thu, 09 Jul 2009 09:26:10 +0000

IanF, no worries.

By: IanF

IanF — Wed, 08 Jul 2009 15:25:12 +0000

Sorry ignore me, it is not the join that is causing the OR condition. I have run Profiler and I am getting superfluos null tests like this:

INNER JOIN [dbo].[BFDStateMachineTypeState] AS [Extent8] ON (([Extent7].[StateMachineTypeID] = [Extent8].[StateMachineTypeID]) [b]OR (([Extent7].[StateMachineTypeID] IS NULL) AND ([Extent8].[StateMachineTypeID] IS NULL)))[/b] AND (([Extent6].[StateID] = [Extent8].[StateID]) [b]OR (([Extent6].[StateID] IS NULL) AND ([Extent8].[StateID] IS NULL)))[/b]

By: IanF

IanF — Wed, 08 Jul 2009 15:13:52 +0000

I can include a little bit, well the bit that is the offending part.

join E in bfd.BFDStateMachineTypeState
on new { D.StateMachineTypeID, A.StateID
equals new { E.StateMachineTypeID, E.StateID }
join L in bfd.BFDStateMachineTypeService
on new { D.StateMachineTypeID, H.ServiceID }
equals new { L.StateMachineTypeID, L.ServiceID }

Thanks,

Ian

By: Deepak

Deepak — Wed, 08 Jul 2009 11:20:43 +0000

Ian,

What does your LINQ query look like? Can you post it here?

By: IanF

IanF — Wed, 08 Jul 2009 11:15:05 +0000

Hi this is great unfortunatley it results in an ‘OR’ for me and not an AND. i.e.:

SELECT [t0].[ShoppingMallId], [t0].[Address],[t0].[PostCode], [t0].[CouncilCode]FROM [dbo].[ShoppingMall] AS [t0]INNER JOIN [dbo].[House] AS [t1]ON ([t0].[CouncilCode] = [t1].[CouncilCode])OR ([t0].[PostCode] = [t1].[PostCode])

By: mike313t

mike313t — Wed, 24 Jun 2009 18:04:50 +0000

What if when joining one condition is an “equals”
and another condition is “not equals”?

By: Deepak

Deepak — Wed, 11 Feb 2009 22:29:21 +0000

mp09ind,

context is my DataContext here which I generated using Visual Studio designer. You can find more details on how to do that here.

http://www.onedotnetway.com/linq-to-sql-tutorial/

By: mp09ind

mp09ind — Wed, 11 Feb 2009 12:37:06 +0000

What is context here?

By: Deepak

Deepak — Mon, 29 Dec 2008 22:27:32 +0000

Thanks for the tip jwright.

By: jwright

jwright — Mon, 29 Dec 2008 18:13:55 +0000

something to keep in mind.
if your joining two tables where the linking columns have different names, the anonymous types’ properties must match.
i.e.,

var query = from s in context.ShoppingMalls
join h in context.Houses
on
new {CouncilCode=s.CouncilCode, PostCode=s.PostCode }
equals
new {CouncilCode=h.District, PostCode=h.ZipCode }
select s;