Question

所以我试图用MSSQL查询中的数据填充DataTable，但由于某种原因它完全拒绝工作，而且它让我非常恼火。

当我使用SqlDataReader和Read（）迭代结果时，我得到了结果，即使我尝试使用SqlDataAdapter填充DataTable，查询也会出现在SQL事件探查器上，但是并没有返回任何结果数据

我不知道我的代码拥有什么，但也许你可以弄明白：

            try
            {
                // Global variables
                var connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString;
                var textString = "Pasākums {0} sākas pēc {1}!";
                var linkString = @"/Event/Index/{0}";

                using (SqlConnection conn = new SqlConnection(connectionString))
                {
                    // Set variables
                    var findIn24HrsEventsCmd = new SqlCommand(@"
                        SELECT adm.UserID, adm.EventID FROM [dbo].[EventAdmissions] AS adm WHERE EventID IN
                        (
                        SELECT EventID FROM [dbo].[Events]
                        WHERE DATEDIFF(hour, @date, StartTime) BETWEEN 0 AND 24
                        )
                        AND 
                        (
                        SELECT COUNT(URL) FROM [dbo].[Notifications]
                        WHERE Type = 1 AND UserID = adm.UserID
                        AND URL LIKE '/Event/Index/'+CAST(adm.EventID AS VARCHAR(36))
                        ) = 0", conn);
                    findIn24HrsEventsCmd.Parameters.Add(new SqlParameter("date", "2015-05-31 02:17:28.727"));

                    var test = new SqlCommand(@"SELECT * FROM [dbo].[EventAdmissions]", conn);

                    var findIn1HrEventsCmd = new SqlCommand(@"
                        SELECT adm.UserID, adm.EventID FROM [dbo].[EventAdmissions] AS adm WHERE EventID IN
                        (
                        SELECT EventID FROM [dbo].[Events]
                        WHERE DATEDIFF(minute, @date, StartTime) BETWEEN 0 AND 60
                        )
                        AND 
                        (
                        SELECT COUNT(URL) FROM [dbo].[Notifications]
                        WHERE Type = 1 AND UserID = adm.UserID
                        AND URL LIKE '/Event/Index/'+CAST(adm.EventID AS VARCHAR(36))
                        ) < 2", conn);
                    findIn1HrEventsCmd.Parameters.Add(new SqlParameter("date", "2015-05-31 02:17:28.727"));
                    var t = findIn1HrEventsCmd.CommandTimeout;

                    // Retrieve data
                    conn.Open();
                    log.Debug("Starting with the events that are on in an hour.");

                    // Do it first for evens within an hour
                    var oneHrDataAdapter = new SqlDataAdapter(test);
                    var oneHrDt = new DataTable();

                    oneHrDataAdapter.Fill(oneHrDt);

                    findIn1HrEventsCmd.Dispose();
                    findIn24HrsEventsCmd.Dispose();
                    oneHrDataAdapter.Dispose();
                }
            } catch (Exception e)
            {
                log.Fatal("Fatal error!" + e.Message);
            }

请注意我是如何将复杂查询替换为一个非常简单的测试查询，该查询肯定会在Management Studio和DataReader中返回结果，但由于某种原因无法使用DataTable。请注意，它不会超时，服务器位于同一台计算机上，查询最多运行1-2秒。

连接有效，因为正如我在DataReader方法之前提到的那样，并且没有抛出异常。

Answer 1

该死的，我从不打扰检查DataTable的Rows属性，结果证明它确实有效。

我认为它没有，因为在调试模式下，Visual Studio会产生误导，因为当您将鼠标悬停在数据表变量上时，它只会显示＆＃34; {}＆＃34;这通常意味着事情是空的。

C＃ - 无论如何，SqlDataAdapter都不会填充DataTable

1 个答案: