Свойство 'POST' для DataMember не найдено в DataSource

        SqlConnection cnn = new SqlConnection(Properties.Settings.Default.KursovayaConnectionString);
 
        DataSet DS = new DataSet(); DataSet DSadrP = new DataSet(); DataSet DSpost = new DataSet();
        
        SqlDataAdapter DAadrP; SqlCommandBuilder BDadrP; BindingSource BD2 = new BindingSource();
        SqlDataAdapter DApost; SqlCommandBuilder BDpost; BindingSource BD1 = new BindingSource();
 
        DataTable TABadrP = new DataTable(); DataRow ROWadrP;
        DataTable TABadrR = new DataTable(); DataRow ROWadrR;
        //DataTable TABimp = new DataTable(); DataRow ROWimp;
        //DataTable TABpost = new DataTable(); DataRow ROWpost;
        //DataTable TABprod = new DataTable(); DataRow ROWprod;
        //DataTable TABreal = new DataTable(); DataRow ROWreal;
        //DataTable TABsup = new DataTable(); DataRow ROWsup;
        
        private void Form1_Load(object sender, EventArgs e)
        {
            this.realizationTableAdapter.Fill(this.dataSetRealization.Realization);
            this.supplyTableAdapter.Fill(this.dataSetSupply.Supply);
            this.productsTableAdapter.Fill(this.dataSetProducts.Products);
            this.aDRESS_REALTableAdapter.Fill(this.dataSetADRESS_REAL.ADRESS_REAL);
            this.implementersTableAdapter.Fill(this.dataSetImplementers.Implementers);
            this.aDRESS_POSTTableAdapter.Fill(this.dataSetADRESS_POST.ADRESS_POST);
            this.pOSTTableAdapter.Fill(this.dataSetPostavki.POST);
 
            constr = Properties.Settings.Default.KursovayaConnectionString;
            SqlConnection cnn = new SqlConnection(constr);
            cnn.Open();
 
            DApost = new SqlDataAdapter("SELECT * FROM POST", cnn);
            BDpost = new SqlCommandBuilder(DApost);
            DApost.Fill(DSadrR, "POST");
            BD1.DataSource = DSpost;
            BD1.DataMember = "POST"; //Свойство 'POST' для DataMember не найдено в DataSource
            GridViewPOST.DataSource = BD1;
            DSpost.Clear();
 
            DAadrP = new SqlDataAdapter("SELECT * FROM ADRESS_POST", cnn);
            BDadrP = new SqlCommandBuilder(DAadrP);
            DAadrP.Fill(DSadrP, "ADRESS_POST");
            BD2.DataSource = DSadrP;
            BD2.DataMember = "ADRESS_POST";
            GridViewADRESS_POST.DataSource = BD2;
            DSadrP.Clear();
        }