我想在VB.net中更新我的数据库数据，但出现错误语法

Question

This is my problem:

When I click update button, I don't know how to fix this error:

My Error Message is:

"Error: syntax error in union query"

This is my code:

Private Sub btnUpdate_Click(sender As Object, e As EventArgs) Handles btnUpdate.Click
    TestConnection()
    Try
        Dim cmd As OleDbCommand
        Dim sql As String
        sql = "(UPDATE tblUsers SET Username = '" & txtUserName.Text & "', Password = '" & txtUserPassword.Text &
                "', Usertype = '" & cbousertype.Text & "', WHERE UserID = '" & txtUserID.Text & "');"
        cmd = New OleDbCommand(sql, Conn)
        cmd.ExecuteNonQuery()
    Catch ex As Exception
        MsgBox("Error: " & ex.Message)
    End Try
End Sub

Is it wrong?

Answer 1

Now my problem has been solved thank you very much i changed my code to use a parameters and then it work Now my code is :

    Private Sub btnUpdate_Click(sender As Object, e As EventArgs) Handles btnUpdate.Click 

    TestConnection()
    Dim cmd As OleDbCommand
    Dim sql As String
    sql = "UPDATE tblUsers SET Username=?, [Password]=?, Usertype=? where UserID=?"
    cmd = New OleDbCommand(sql, Conn)
    cmd.Parameters.AddWithValue("@p1", txtUserName.Text)
    cmd.Parameters.AddWithValue("@p2", txtUserPassword.Text)
    cmd.Parameters.AddWithValue("@p3", cbousertype.Text)
    cmd.Parameters.AddWithValue("@p4", txtUserID.Text)
    cmd.ExecuteNonQuery()
    MsgBox("Data Has Been Updated", MsgBoxStyle.Information, "Updated")
    ShowUser()
End Sub