Syntax error in update statement using an MS Access database

Question

I have inserted my record successfully with the OleDbCommand and parameters, but if I update the record I get the following error:

Syntax Error!

I have tried put the square brackets around the Field Name, and it still does not work. But if I copy the command to update with Access query, it works.

Code:

Public Function update() As Boolean
    Dim STATE As Boolean = False
    Dim cmd As New OleDbCommand
    cmd.Connection = cn
    cmd.CommandType = CommandType.Text
    cmd.CommandText = "UPDATE [GUEST_DATA_TBL] SET [USD]=@USD, [RIEL]=@RIEL, [EURO]=@EURO, [BAHT]=@BAHT, [AUSD]=@AUSD, [GIFT]=@GIFT, [MEMO]=@MEMO WHERE [ID]=@ID"
    AssignParams(cmd)
    cmd.ExecuteNonQuery()
    Return STATE
End Function

'the parameters

Private Sub AssignParams(cmd As OleDbCommand)
        cmd.Parameters.AddWithValue("@ID", ID)
        cmd.Parameters.AddWithValue("@USD", USD)
        cmd.Parameters.AddWithValue("@RIEL", RIEL)
        cmd.Parameters.AddWithValue("@BAHT", BAHT)
        cmd.Parameters.AddWithValue("@EURO", EURO)
        cmd.Parameters.AddWithValue("@AUSD", AUSD)
        cmd.Parameters.AddWithValue("@GIFT", GIFT)
        cmd.Parameters.AddWithValue("@MEMO", MEMO)
End Sub

Answer 1

First it's good to see that you are already using parameters but with MS Access, the order of the parameters is important not the names. I use the ? placeholder within my SQL command when using parameters. I also specify the data type so consider using the OleDbParameter Constructor (String, OleDbType) to add your parameters.

I would also consider implementing Using :

Managed resources are disposed of by the .NET Framework garbage collector (GC) without any extra coding on your part. You do not need a Using block for managed resources. However, you can still use a Using block to force the disposal of a managed resource instead of waiting for the garbage collector.

You could implement a check for the value returned by ExecuteNonQuery() to see how many rows were effected.

Lastly, with VB.NET by not specifying a modifier here; Private Sub AssignParams(cmd As OleDbCommand) , the compiler by default will use ByVal :

Specifies that an argument is passed in such a way that the called procedure or property cannot change the value of a variable underlying the argument in the calling code.

You should be using ByRef :

Specifies that an argument is passed in such a way that the called procedure can change the value of a variable underlying the argument in the calling code.

Your code would look something like this:

Public Function update() As Boolean

    Dim STATE As Boolean = False

    Using con As OleDbConnection = cn,
          cmd As New OleDbCommand("UPDATE [GUEST_DATA_TBL] SET [USD]=?, [RIEL]=?, [EURO]=?, [BAHT]=?, [AUSD]=?, [GIFT]=?, [MEMO]=? WHERE [ID]=?", con)

        con.Open()

        AssignParams(cmd)

        Dim rowsAffected As Integer = cmd.ExecuteNonQuery()

        If rowsAffected > 0 Then
            STATE = True
        End If

    End Using

    Return STATE

End Function

Private Sub AssignParams(ByRef cmd As OleDbCommand)
    cmd.Parameters.Add("@USD", OleDbType.[Type]).Value = USD
    cmd.Parameters.Add("@RIEL", OleDbType.[Type]).Value = RIEL
    cmd.Parameters.Add("@EURO", OleDbType.[Type]).Value =  EURO
    cmd.Parameters.Add("@BAHT", OleDbType.[Type]).Value =  BAHT
    cmd.Parameters.Add("@AUSD", OleDbType.[Type]).Value =  AUSD
    cmd.Parameters.Add("@GIFT", OleDbType.[Type]).Value = GIFT
    cmd.Parameters.Add("@MEMO", OleDbType.[Type]).Value = MEMO
    cmd.Parameters.Add("@ID", OleDbType.[Type]).Value = ID
End Sub

Note that I have used OleDbType.[Type] . You will want to replace [Type] with the data type you've used on your database.

Answer 2

Private Sub AssignParams(cmd As OleDbCommand)
   cmd.Parameters.AddWithValue("@USD", USD)
   cmd.Parameters.AddWithValue("@RIEL", RIEL)
   cmd.Parameters.AddWithValue("@EURO", EURO)
   cmd.Parameters.AddWithValue("@BAHT", BAHT)       
   cmd.Parameters.AddWithValue("@AUSD", AUSD)
   cmd.Parameters.AddWithValue("@GIFT", GIFT)
   cmd.Parameters.AddWithValue("@MEMO", MEMO)
   cmd.Parameters.AddWithValue("@ID", ID)
End Sub