.NET----事务

 

一直说事务事务的，明白咋用但一直都没用过。现在做删除图书的时候终于用到了，因为同时还要删除图书的分类。因为一本书有多个分类，因此把图书ID和分类ID单放到一个表里。删的时候先删这个表的数据（因为是外键表嘛~），再删图书表的数据。
/// <summary>
        /// 删除一本图书
        /// </summary>
        /// <param name="iProductID">要删除的图书ID</param>
        public int DeleteProduct(int iProductID)
        {
            int iRow = 0;
            string strSql = String.Empty;
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = DBHelp.GetConnection();
            SqlTransaction tran = conn.BeginTransaction();
            cmd.Connection = conn;
            cmd.CommandType = CommandType.Text;
            cmd.Transaction = tran;
            try
            {
                strSql = new StringBuilder()
                    .AppendFormat("DELETE FROM ProductCategory WHERE (ProductID = {0})", iProductID).ToString();
                cmd.CommandText = strSql;
                iRow = cmd.ExecuteNonQuery();
                strSql = new StringBuilder()
                    .AppendFormat("DELETE FROM Product WHERE (ProductID = {0})", iProductID).ToString();
                cmd.CommandText = strSql;
                iRow = cmd.ExecuteNonQuery();
                tran.Commit();
            }
            catch (Exception ex)
            {
                iRow = 0;
                tran.Rollback();
            }
            finally
            {
                conn.Close();
            }
            return iRow;
        }