private void DoLoadConstraints() { if (_helper != null && constraints.Count == 0 && !_isLoadConstraints) { string sql = "select a.constraint_name,a.table_name,a.column_name,b.constraint_type,b.status,b.index_name from user_cons_columns a,user_constraints b where a.table_name=b.table_name and a.constraint_name=b.constraint_name and a.position=1 and a.table_name='" + table_name + "'"; DataTable dt = _helper.ExecuteDataTable(sql); foreach (DataRow item in dt.Rows) { OracleTableConstraintsClass otcc = new OracleTableConstraintsClass(item); constraints.Add(otcc); } _isLoadConstraints = true; } }