Linq2Sql select where string is NOT null or empty

Question

I'm trying to pull records from a table (with join) where a text field PassFail must not = PASS not be null/empty but I'm struggling with the syntax. The errors I have had so far point to the syntax I'm using is not supported by linq..

My latest attempt is

Dim HW2Process = (From mi In dc.tblMainDatas
                            Join u In dc.tblUsers On u.UserNo Equals mi.RecdBy
                            Join fi In dc.tblHWs On fi.HWRef Equals mi.HWRef
                            Where mi.Ref.StartsWith(tb_HWRefFind.Text.Trim()) And mi.DateProcessed.HasValue = True And ((mi.PassFail <> "PASS") And (IsNothing(mi.PassFail) = False))
                            Select New With {.ID = mi.ID,
                                                .DateReceived = mi.DateRecd,
                                                .ReceivedBy = u.FullName,
                                                .SerialID = mi.SerialID,
                                                .LiveTest = mi.LiveTest,
                                                .DeployYear = mi. DeployYear,
                                                .ProductType = mi.ProductType,
                                                .HWRef = mi.HWRef,
                                                .HWName = fi.HWName,
                                                .MediaType = mi.MediaType,
                                                .MediaQuantity = mi.MediaQty})

The criteria should be that mi.PassFail should not be null or empty or equal 'PASS'

Any help appreciated.

Answer 1

You write:

mi.DateProcessed.HasValue = True

Linq2SQL don't have right translation for this. You should write like this:

(Not (mi.DateProcessed Is Nothing))

I suppose same thing here:

(IsNothing(mi.PassFail) = False))

If you want translation of what i see here should be:

(Not (mi.PassFail Is Nothing))

I'm not really in VB, main in C# but i think you get this error becouse if you want to check some value on null you should do it like i mension.