CODEWITHSUNDEEP
vb.netlinqreadonly
Michael Stramel
Michael Stramel

Reputation: 1387

linq query read only

I am completely stumped on this issue. I have been searching for a while now and still have no answer for how to solve the problem.

I run a query in which I attempt to set the value on. The problem is that they come up as read only variables if I do not specify Select New With. When I specify Select New With it doesn't update the database. Some of the code is listed below.

My goal is to allow the shooter to update the DataGridView which would update the database. I was told in another question on StackOverflow that the DataGridView would not update the database simply by the user inputting data. So I created a update button which runs the code listed below.

Code:

Query using Select New With allows me to edit variables but won't commit to database:

Dim query = From t In db.Trophies _
            Select New With {t.TrophyName, t.WinnerId, t.Name, t.Score, t.Printed}

Query won't let me edit variables. Error message reads "Property 'TrophyName' is 'ReadOnly':

Dim query = From t In db.Trophies _
            Select t.TrophyName, t.WinnerId, t.Name, t.Score, t.Printed

Code where I want to update the results:

Dim i as integer = 0
For Each result In query
    result.WinnerId = dgvTrophies.Rows(i).Cells(dgvTrophies.Columns("WinnerId").Index).Value
    result.Name = dgvTrophies.Rows(i).Cells(dgvTrophies.Columns("Name").Index).Value
    result.Score = dgvTrophies.Rows(i).Cells(dgvTrophies.Columns("Score").Index).Value
    db.SubmitChanges()
    i += 1
Next

Table:

PRIMARY KEY TrophyId int auto-increments
TrophyName varchar(50)
WinnerId char(7) Allow Nulls
Name varchar(20) Allow Nulls
Score int Allow Nulls
Printed bit

Any advice or answers would be greatly appreciated.

EDIT: I've tried setting ObjectTrackingEnabled to True but it didn't solve the issue.

EDIT: To get it to do a more "automatic" update, after the user leaves edit mode on the DataGridView I call db.SubmitChanges which updates the database and no longer requires an update button.

Upvotes: 2

Views: 2939

Answers (1)

Magnus
Magnus

Reputation: 46997

Using Select new with { ... creates an anonymous object, and changes to that is not submited to the database. You need to work with the linq entities. For Example:

Dim query = From t In db.Trophies _
            Select t

Or simply 

Dim query = db.Trophies

That will work.

Upvotes: 2

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