事务的回滚对于拥有自增主键的表来说，insert的数据是被删除，update和delete的数据是被恢复

事务的回滚对于拥有自增主键的表来说，insert的数据是被删除，update和delete的数据是被恢复

建表代码：create table users(userid int primary key identity(1,1),uname varchar(100),utime datetime)

c#调用代码        private void selectInsertSelectUpdateSelectDeleteSelect()        {            SqlConnection conn = getConn();            SqlTransaction tran = null;            try            {                conn.Open();                tran = conn.BeginTransaction();                SqlDataAdapter cmdSelect = new SqlDataAdapter("select * from users", conn);                cmdSelect.SelectCommand.Transaction = tran;                DataTable dtSelect = new DataTable();                SqlCommand cmdInsert = new SqlCommand("insert into users(uname, utime) values('cc', GETDATE())", conn);                cmdInsert.Transaction = tran;                SqlDataAdapter cmdSelect_1 = new SqlDataAdapter("select * from users", conn);                cmdSelect_1.SelectCommand.Transaction = tran;                DataTable dtSelect_1 = new DataTable();                SqlCommand cmdUpdate = new SqlCommand("update users set utime=getdate()", conn);                cmdUpdate.Transaction = tran;                SqlDataAdapter cmdSelect_2 = new SqlDataAdapter("select * from users", conn);                cmdSelect_2.SelectCommand.Transaction = tran;                DataTable dtSelect_2 = new DataTable();                SqlCommand cmdDelete = new SqlCommand("delete from users where userid=(select MAX(userid) from users)", conn);                cmdDelete.Transaction = tran;                SqlDataAdapter cmdSelect_3 = new SqlDataAdapter("select * from users", conn);                cmdSelect_3.SelectCommand.Transaction = tran;                DataTable dtSelect_3 = new DataTable();                cmdSelect.Fill(dtSelect);                bindData(dtSelect, gv);                cmdInsert.ExecuteNonQuery();                cmdSelect_1.Fill(dtSelect_1);                bindData(dtSelect_1, gv1);                cmdUpdate.ExecuteNonQuery();                cmdSelect_2.Fill(dtSelect_2);                bindData(dtSelect_2, gv2);                cmdDelete.ExecuteNonQuery();                cmdSelect_3.Fill(dtSelect_3);                bindData(dtSelect_3, gv3);                /*                 * 此处丢异常，然后回滚                */                int x = 1;                int y = 0;                int z = x / y;                tran.Commit();            }            catch (Exception ex)            {                tran.Rollback();                Response.Write("fuck  有异常，老子回滚了");            }            finally            {                conn.Close();            }        }        private void bindData(DataTable dt, GridView gv)        {            gv.DataSource = dt;            gv.DataBind();        }        private SqlConnection getConn()        {            string connStr = "server=.;uid=sa;pwd=123456;database=test;";            return new SqlConnection(connStr);        }