I am inheriting a form class (Form1) for Form 2. Form 1 code works without error. In Form 1, I use SqlCommandBuilder(SQL.DBDA).GetUpdateCommand
to generate the update command for my Datagrid to pass to SQL data table which again works perfectly and the table is updated successfully. The SQL command text for Form 1 Update is shown here:
In Form 2, I write the following for the update command, where the only difference is Selecting the Table shown here:
SQL.ExecQuery("SELECT * FROM dtbRateVerse;")
SQL.DBDA.UpdateCommand = New SqlClient.SqlCommandBuilder(SQL.DBDA).GetUpdateCommand
MsgBox(SQL.DBDA.UpdateCommand.CommandText)
SQL.DBDA.Update(SQL.DBDT)
The command text for this update command is shown here:
It is not dissimilar to the successful update command shown in Form1 (image 1). Still, no data is passed to the SQL from the Gridview.
I also tried writing a dynamic Update statement without using the command builder shown below. The text of this statement generates an accurate SQL command but again, nothing passed to the database. This code is shown here:
For i = 1 To colEnd
colName.Add("[" & DataGridView1.Columns(i).HeaderText.ToString & "]")
Next
For i = 1 To colEnd
For y = 0 To Me.DataGridView1.RowCount - 1
For n = 1 To colEnd
gridVals.Add(DataGridView1.Rows(y).Cells(n).Value.ToString)
Next
With Me.DataGridView1
SQL.AddParam("@PrimKey", .Rows(y).Cells(0))
cmdUpdate = "UPDATE " & tbl_Name & " SET " & colName.Item(i - 1) & "=" & gridVals.Item(i - 1) & " WHERE ID=@PrimKey;"
SQL.ExecQuery(cmdUpdate)
End With
Next
Next
If anyone has any ideas/ solutions on what I need to do to get the update command working properly, I’d really appreciate it. Thanks!
Added ExecQuery methdod per request below:
Public Class SQLControl
Private DBConnect As New SqlConnection("SERVER STRING HERE")
Private DBCmd As SqlCommand
'DB DATA
Public DBDA As SqlDataAdapter
Public DBDT As DataTable
'QUERY PARAMETERS
Public Params As New List(Of SqlParameter)
'QUERY STATISTICS
Public RecordCount As Integer
Public Exception As String
Public Sub New()
End Sub
'ALLOW CONNECTION STRING OVERRIDE
Public Sub New(ConnectionString As String)
DBConnect = New SqlConnection(ConnectionString)
End Sub
'EXECUTE QUERY SUB
Public Sub ExecQuery(Query As String)
'RESET QUERY STATS
RecordCount = 0
Exception = ""
Try
DBConnect.Open()
'CREATE DATABASE COMMAND
DBCmd = New SqlCommand(Query, DBConnect)
'LOAD PARAMS INTO DB COMMAND
Params.ForEach(Sub(p) DBCmd.Parameters.Add(p)) 'LAMBDA EXPRESSION
'CLEAR PARAMS LIST
Params.Clear()
'EXECUTE COMMAND & FILL DATASET
DBDT = New DataTable
DBDA = New SqlDataAdapter(DBCmd)
RecordCount = DBDA.Fill(DBDT)
Catch ex As Exception
'CAPTURE ERROR
Exception = "ExecQuery Error: " & vbNewLine & ex.Message
Finally
'CLOSE CONNECTION
If DBConnect.State = ConnectionState.Open Then DBConnect.Close()
End Try
End Sub
'ADD PARAMS
Public Sub AddParam(Name As String, Value As Object)
Dim NewParam As New SqlParameter(Name, Value)
Params.Add(NewParam)
End Sub
'ERROR CHECKING
Public Function HasException(Optional Report As Boolean = False) As Boolean
If String.IsNullOrEmpty(Exception) Then Return False
If Report = True Then MsgBox(Exception, MsgBoxStyle.Critical, "Exception:")
Return True
End Function
End Class
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Answer
The issue appears to be as I suspected it was. Here’s for code from the form:
SQL.ExecQuery("SELECT * FROM dtbRateVerse;")
SQL.DBDA.UpdateCommand = New SqlClient.SqlCommandBuilder(SQL.DBDA).GetUpdateCommand
SQL.DBDA.Update(SQL.DBDT)
In that, you first call ExeQuery
and finally call Update
on the data adapter and pass the DBDT
DataTable
. In your ExecQuery
method, you have this:
DBDT = New DataTable
DBDA = New SqlDataAdapter(DBCmd)
RecordCount = DBDA.Fill(DBDT)
That means that the first code snippet is going to be calling Update
and passing a DataTable
that was just freshly created and populated. Why would you expect that DataTable
to have any changes in it to save? This is an example of why I think DAL classes like this are garbage.
If you’re going to be using a class like that then you should be creating a command builder inside it when you create the data adapter, e.g.
'DB DATA
Public DBDA As SqlDataAdapter
Public DBCB As SqlCommandBuilder
Public DBDT As DataTable
and:
'EXECUTE COMMAND & FILL DATASET
DBDT = New DataTable
DBDA = New SqlDataAdapter(DBCmd)
DBCB = New SqlCommandBuilder(DBDA)
RecordCount = DBDA.Fill(DBDT)
Now there’s no need to call ExecQuery
again or create your own command builder. Just call ExecQuery
once when you want the data, get the populated DataTable
, use it and then call Update
on the data adapter and pass that DataTable
when it’s time to save.
That said, you don’t even necessarily need to change that class. If you already have an instance and you already called ExecQuery
then it already contains the data adapter and the DataTable
. You can still create your own command builder if you want but just don’t call ExecQuery
again and lose the objects you already had. If you changed that first code snippet to this:
Dim commandBuilder As New SqlClient.SqlCommandBuilder(SQL.DBDA)
SQL.DBDA.Update(SQL.DBDT)
Then it would work, assuming that you are using the same SQLControl
instance as you used to get the data in the first place.