C#

System.NullReferenceException: Object reference not set to an instance of an object.
at PriceList.frmMain.populate_family_physician()
at PriceList.frmMain.frmMain_Load(Object sender, EventArgs e)

Sandeep Mewara wrote:

This error happens when you try to use a property of an object that is null.
More details:

private void populate_family_physician()
{
    this.Cursor = Cursors.WaitCursor;

    data_table = new DataTable();

    sql_connection = new MySqlConnection(ConfigurationManager.ConnectionStrings["SQLdb"].ConnectionString);

    // try
    // {
    sql_connection.Open();
    sql_command = new MySqlCommand("sp_get_pricelist_by_code", sql_connection);
    sql_command.CommandType = CommandType.StoredProcedure;
    sql_command.Parameters.AddWithValue("param_pricelist_code", "FamilyPhysician").MySqlDbType = MySqlDbType.VarChar;
    sql_adapter = new MySqlDataAdapter(sql_command);
    sql_adapter.Fill(data_table);
    dataFamilyPhysician.DataSource = null;
    dataFamilyPhysician.ResetBindings();
    dataFamilyPhysician.DataSource = data_table;

    gridFamilyPhysician.Columns["price_list_id"].Caption = "price_list_id";
    gridFamilyPhysician.Columns["price_list_id"].AppearanceHeader.TextOptions.HAlignment = DevExpress.Utils.HorzAlignment.Center;
    gridFamilyPhysician.Columns["price_list_id"].AppearanceCell.TextOptions.HAlignment = DevExpress.Utils.HorzAlignment.Center;
    gridFamilyPhysician.Columns["price_list_id"].Width = 80;
    gridFamilyPhysician.Columns["price_list_id"].Visible = false;

    gridFamilyPhysician.Columns["price_list_description"].Caption = "Description";
    gridFamilyPhysician.Columns["price_list_description"].AppearanceHeader.TextOptions.HAlignment = DevExpress.Utils.HorzAlignment.Default;
    gridFamilyPhysician.Columns["price_list_description"].AppearanceCell.TextOptions.HAlignment = DevExpress.Utils.HorzAlignment.Default;
    gridFamilyPhysician.Columns["price_list_description"].Width = 150;

    gridFamilyPhysician.Columns["price_list_price"].Caption = "Price";
    gridFamilyPhysician.Columns["price_list_price"].AppearanceHeader.TextOptions.HAlignment = DevExpress.Utils.HorzAlignment.Center;
    gridFamilyPhysician.Columns["price_list_price"].AppearanceCell.TextOptions.HAlignment = DevExpress.Utils.HorzAlignment.Center;
    gridFamilyPhysician.Columns["price_list_price"].DisplayFormat.FormatType = DevExpress.Utils.FormatType.Numeric;
    gridFamilyPhysician.Columns["price_list_price"].DisplayFormat.FormatString = "#,###,##0.000";
    gridFamilyPhysician.Columns["price_list_price"].Width = 50;

    this.Cursor = Cursors.Default;
}

SELECT A.*, B.* --please, replace with the fields you really need...
FROM A
INNER JOIN B
ON A.A = B.A
WHERE (A.B <> B.B 
        OR A.C <> B.C 
        OR DATEADD(hour, 2, A.D) <> B.D --adding two hours to hour in ET converts it to hour in MT
        OR A.E <> B.E) --replace with checks for the fields that you care about

SELECT A.*, B.* --please, replace with the fields you really need...
FROM A
FULL OUTER JOIN B
ON A.A = B.A AND <OTHERS>
WHERE A.A IS NULL OR B.A IS NULL