Member Avatar for sw8revenge

hello everyone i just wanna ask some help regarding on how to delete all datas in the data grid view from search result.

i have a form which search data in specific date and show result in the datagridview, what i want is that when delete button is clicked all datas that in the datagridview will be deleted sameway in the database

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  • Latest Post Latest Post by artemix22

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asked how to delete every row shown in a DataGridView and have the same rows removed from the database. shared a reference and suggested a row‑by‑row delete, but hit "Parameters @myParam has already been defined." That error comes from re-adding a parameter with the same name to the same SqlCommand on every loop iteration.

Easiest fix (minimal change): add the parameter once and set its Value each iteration — don’t call AddWithValue repeatedly. Example (VB.NET):

Using cn As New SqlConnection(connString)
  cn.Open()
  Using cmd As New SqlCommand("DELETE FROM table1 WHERE RecID = @RecID", cn)
    cmd.Parameters.Add("@RecID", SqlDbType.Int)
    For Each row As DataGridViewRow In DataGridView1.Rows
      If Not row.IsNewRow Then
        cmd.Parameters("@RecID").Value = CInt(row.Cells("RecID").Value)
        cmd.ExecuteNonQuery()
      End If
    Next
  End Using
End Using

A better approach (recommended): perform a single DELETE that matches the same filter you used to populate the grid — e.g., delete by date range — or batch the keys into one command. Single-statement deletes are faster, atomic, and simpler to audit:

Using cn As New SqlConnection(connString)
  Using cmd As New SqlCommand("DELETE FROM table1 WHERE MyDate BETWEEN @Start AND @End", cn)
    cmd.Parameters.Add("@Start", SqlDbType.DateTime).Value = startDate
    cmd.Parameters.Add("@End", SqlDbType.DateTime).Value = endDate
    cn.Open()
    Dim rowsDeleted = cmd.ExecuteNonQuery()
  End Using
End Using

If the grid is data‑bound, prefer marking rows deleted in the DataTable and calling SqlDataAdapter.Update so the UI and DB stay in sync. Always verify with a SELECT first, wrap multi‑row deletes in a transaction, and refresh the grid after the operation.

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Member Avatar for M.Waqas Aslam

hello !
you can perform your required function like this

dim myCon as new sqlconnection("connection string")
dim cmd as new sqlcommand
dim i as integer
myCon.open()
for i = 0 to datagrid1.rows.count -1 
   cmd.commandtext = "delete from table1 where RecID=@RecID"
   cmd.connection = myCon
   cmd.parameter.addwithvalue("@RecID",datagrid1.item(0,i).value)
   cmd.executenonquery()
next
myCon.close

i write this code here in posting thread textbox so may be there is some spelling mistake , but i hope even if this will not solve your prob but this will give you a idea to solve your prob.(sorry for bad english)

Regards

M.Waqas Aslam

Member Avatar for artemix22

hello !
you can perform your required function like this

dim myCon as new sqlconnection("connection string")
dim cmd as new sqlcommand
dim i as integer
myCon.open()
for i = 0 to datagrid1.rows.count -1 
   cmd.commandtext = "delete from table1 where RecID=@RecID"
   cmd.connection = myCon
   cmd.parameter.addwithvalue("@RecID",datagrid1.item(0,i).value)
   cmd.executenonquery()
next
myCon.close

i write this code here in posting thread textbox so may be there is some spelling mistake , but i hope even if this will not solve your prob but this will give you a idea to solve your prob.(sorry for bad english)

Regards

M.Waqas Aslam

it give me this error :

"Parameters @myParam has already been defined"

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