Exception error when importing datagridview to Oracle

[csharp learner]

Hi, I'm trying to update a datagrid view table to the Oracle DB.
This is my code so far....

// Connection to Oracle DB   
 int connectionCounter = 0;   
                bool boolUpdateData = true;   
                while (boolUpdateData && connectionCounter < 3)   
                {   
                    try   
                    {   
                        localConnection = new OracleConnection(localFunction.localConnectionString);   
                        localConnection.Open();   
 
                        boolUpdateData = false;   
                    }   
                    catch (Exception localException)   
                    {   
                        localFunction.WriteEventLog(localException.ToString(), "OPCAlarmConfig");   
                    }   
                    connectionCounter++;   
                }   
 
                localSQL = @"SELECT * FROM SYS_LINE";   
                localFunction.ExecuteOracleNonQuery(localSQL, localConnection, "OPCAlarmConfig");   
 
// Update Oracle DB   
         try {   
            OracleCommandBuilder cb = new OracleCommandBuilder(oleda);   
            userTable = ds.Tables["SYS_LINE"];   
            oleda.Fill(ds,"SYS_LINE");   
            excelGridView.DataSource = ds.Tables[0];   
            oleda.Update(ds, "SYS_LINE");   
              }   
                catch (Exception imptoracle)   
                { MessageBox.Show(imptoracle.ToString()); }   
            }   
 

This exception error "Object reference not set to an instance of an object" kept appearing on the "oleda.Fill(ds, "SYS_LINE") ;" line

Can anyone help?

[Curtis Rutland]

Well, you haven't shown us in this code where you instantiate your DataAdapter object (oleda). Without that, I can't tell exactly whats wrong.

It looks like you either never instantiated it, or you never set it's select command, based on the error.

[csharp learner]

This is where my form loads.

public void displayexcel_Load(object sender, EventArgs e)
        {
            try
            {
                string connString = "provider=Microsoft.Jet.OLEDB.4.0;data source=" + gotdirectory + @";Extended Properties=""Excel 8.0;HDR=YES;""";
                OleDbConnection oledbConn = new OleDbConnection(connString);
                oledbConn.Open();
                OleDbCommand cmd = new OleDbCommand("SELECT * FROM [A2:O36]", oledbConn);
                OleDbDataAdapter oleda = new OleDbDataAdapter();
                oleda.SelectCommand = cmd;
                oleda.Fill(ds);
                userTable = ds.Tables[0];
                excelGridView.DataSource = ds.Tables[0].DefaultView;
                excelGridView.ReadOnly = true;
                oledbConn.Close();
            }
            catch (Exception displayerror)
            {
                MessageBox.Show(displayerror.ToString());
            }
        }