asked on

Delete Rows from Dataset

I am trying to delete rows from a Dataset based on a certain condition being met. I am using the following code which validates the condition but not all of the rows that show be deleted are deleted. I am hoping someone can shed some light on what I am doing wrong.

For i As Integer = 0 To ds.Tables("search_result").Rows.Count - 1

Dim dr As DataRow = ds.Tables("search_result").Rows(i)

If Check_Status(dr("IDNum")) = False Then
dr.Delete()
End If

Next i

ds.Tables("search_result").AcceptChanges()

Moe DeShong

I didn't try this but my guess is when you delete a row you are changing the row count so some of the rows are being skipped. You should probably mark the row for deletion in some way then come back and delete all the marked rows at once. Maybe programatically add a boolean column and set it to true if it needs deleted.

Tommy11b

When you delete a row from a datatable or dataset, it marks the RowState appropiately, So in this case your marking these rows as "deleted". After this you would then call an update method to make the changes in your actual database. HOWEVER by explicitly calling the AcceptChanges method of your dataset/datatable, you are changing the RowState on each row back to "Unmodified".

Kumaraswamy R

http://www.codeguru.com/forum/showthread.php?t=256573

Mike_Stevens

ASKER

The changes that I am making are dont have to be save back to a dataset. What i am doing is populating a dataset with records and then if certain records meet a specific criteria i want to remove the from the dataset populate a datagridview with the records in the dataset.

Tommy11b

Ok, in that case just remove the AcceptChanges line which is essientially Un-deleting your datarow records. If that still doesnt work, try the remove method instead of delete.

Mike_Stevens

ASKER

I removed the acceptchanges with no lock. cant use remove on datarow

Tommy11b

If you step thru your code, are you sure any of the rows are being deleted? I would set a break point on Line: dr.Delete(), just to confirm the delete to start.

Tommy11b

Also your deleting a variable of the datarow, so not sure if that will be persisted back to your dataset or not. I would do the delete straight from ds.Tables("search_result").Rows(i)

Mike_Stevens

ASKER

Yes...the delete function is deleting the rows that match the criteria for rows that should be deleted.

Tommy11b

Just guessing but I'm wondering if you have multiple datasets, where your deleting from one dataset but have the datagridview results bound to a different one.

Mike_Stevens

ASKER

Yes...the rows are being deleted

Tommy11b

Can you attach an example, so I can take a crack at it. Preferably with an xml file since I dont have your db access...

Mike_Stevens

ASKER

The dataset set is being populated correctly...the issue is with removing select rows. He is the code that does that.

For i As Integer = 0 To ds.Tables("search_result").Rows.Count - 1

If Check_Status(ds.Tables("search_result").Rows(0).Item("IDNum").ToString) = True Then
ds.Tables("search_result").Rows(i).Delete()
End If

Next

ASKER CERTIFIED SOLUTION

Nasir Razzaq

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