static SqlDatabaseHelper() { try { SqlDatabaseHelper._connectionString = ConfigurationManager.ConnectionStrings["VinaERPConnection"].ConnectionString; SqlDatabaseHelper.database = new SqlDatabase(SqlDatabaseHelper._connectionString); SqlDatabaseHelper.lstPrimaryColumns = SqlDatabaseHelper.GetAllTablePrimaryColumns(); SqlDatabaseHelper.NotNullTableColumns = new SortedList <string, DataColumnCollection>(); SqlDatabaseHelper.ForeignTableColumns = new SortedList <string, DataColumnCollection>(); } catch (Exception ex) { int num = (int)MessageBox.Show(ex.Message); } }