public class sqlservershiwu    {        public string sqlconString = "Data Source=.;Initial Catalog=TestDB;User ID=sa;Password=123456789";        public void findAll()        {            bool flag = false;            int result = 0;            using (SqlConnection con = new SqlConnection(sqlconString))            {                con.Open();                SqlCommand com = new SqlCommand();                com.CommandType = System.Data.CommandType.Text;                com.Connection = con;                //共享锁                SqlTransaction st = con.BeginTransaction(IsolationLevel.ReadCommitted);                //开始执行事务                com.Transaction = st;                try                {                    string sql1 = "delete from testTable where id = 1";                    com.CommandText = sql1;                    result += com.ExecuteNonQuery();                    string sql2 = "delete from testTable where id = 2";                    com.CommandText = sql2;                    result += com.ExecuteNonQuery();                    string sql3 = "delete from testTable where id = q";                    com.CommandText = sql3;                    result += com.ExecuteNonQuery();                    string sql4 = "insert into testTable(id,name)values(‘3‘,‘3‘)";                    com.CommandText = sql4;                    result += com.ExecuteNonQuery();                    //提交事务                    st.Commit();                    flag = true;                }                catch (Exception ex)                {                    flag = false;                    //事务回滚                    st.Rollback();                    throw ex;                }            }        }    }