private static readonly string strCon = " server=.;database=test;uid=sa;pwd=123 " ; SqlConnection con = new SqlConnection(strCon); public string aaa() ... { con.Open(); SqlTransaction sta = con.BeginTransaction(IsolationLevel.ReadCommitted, "aaa"); SqlCommand cmd = con.CreateCommand(); cmd.Connection = con; cmd.Transaction = sta; try ...{ cmd.CommandText = "insert into t1 (tAction) values ('a3')"; cmd.ExecuteNonQuery(); cmd.CommandText = "insert into t1 (tAction) values ('a4')"; cmd.ExecuteNonQuery(); sta.Commit(); return "success"; } catch (Exception e) ...{ try ...{ sta.Rollback(); } catch (SqlException ex) ...{ if (sta.Connection != null) ...{ return "An exception of type " + ex.GetType().ToString(); } } return e.GetType().ToString(); } finally ...{ con.Close(); } }