public string mdb_exe_return(string sql) { data_conn cn = new data_conn(); OleDbConnection connection1 = cn.mdb_conn(); OleDbCommand command1; connection1.Open(); OleDbDataAdapter da = new OleDbDataAdapter(); DataSet ds = new DataSet(); command1 = new OleDbCommand(sql, connection1); command1.ExecuteNonQuery(); command1 = new OleDbCommand("select @@identity", connection1); da.SelectCommand = command1; da.Fill(ds, "aa"); connection1.Close(); return ds.Tables["aa"].Rows[0][0].ToString(); }