无法在查询中订购答案

【问题标题】：Can't order in query无法在查询中订购
【发布时间】：2014-09-27 08:16:31
【问题描述】：

我有一个需要排序的查询，然后我需要从中选择特定的行。

错误：

附加信息：ORDER BY 子句在视图、内联函数、派生表、子查询和公用表表达式中无效，除非还指定了 TOP、OFFSET 或 FOR XML。

我想要做的是：

"SELECT * FROM (SELECT" +
                        " Websites.Id as websiteId, " +
                        " Websites.Title, " +
                        " Websites.Description, " +
                        " Websites.Url, " +
                        " Websites.BannerURL,  " +
                        " (Select Count(*) From Votes where WebsiteID = Websites.Id And [Unique] = 1 And Date = '" +
                        Date + "') as TotalVotes, " +
                        " ISNULL((Select AVG(rating) From WebsiteRating where WebsiteID = Websites.Id), 5) as Rating, " +
                        " Users.Username, " +
                        " (Select Count(*) From Redirects where WebsiteID = Websites.Id And [Unique] = 1 And Date = '" +
                        Date + "') as Redirects, " +
                        " RowNum = ROW_NUMBER() OVER (ORDER BY Websites.ID) " +
                        " FROM Websites " +
                        " INNER JOIN Users ON Websites.UserID = Users.Id " +
                        " Where Websites.Enabled = 1" +
                        " GROUP BY Websites.Title, Websites.Description, Websites.Url, Websites.BannerURL , Users.Username, Websites.Id" +
                        // Error
                        " ORDER BY Websites.Id DESC" +
                        ") as Table1 " +
                        "WHERE RowNum > " + number + " And RowNum <= " + amount + "";

当我在以下之后下订单时：

"WHERE RowNum > " + number + " And RowNum <= " + amount + "";

然后它首先选择从 0 到 25 的行，然后对其进行排序。但我想先订购它，然后从该列表中选择第 25 行中的第 0 行。

我还是 sql 的初学者，一直使用 Linq。但这是我的一个旧项目，仍然可以使用普通 sql。

【问题讨论】：

标签： sql-server sql-order-by

【解决方案1】：

试试这个：

"SELECT * FROM (SELECT" +
    " Websites.Id as websiteId, " +
    " Websites.Title, " +
    " Websites.Description, " +
    " Websites.Url, " +
    " Websites.BannerURL,  " +
    " (Select Count(*) From Votes where WebsiteID = Websites.Id And [Unique] = 1 And Date = '" +
    Date + "') as TotalVotes, " +
    " ISNULL((Select AVG(rating) From WebsiteRating where WebsiteID = Websites.Id), 5) as Rating, " +
    " Users.Username, " +
    " (Select Count(*) From Redirects where WebsiteID = Websites.Id And [Unique] = 1 And Date = '" +
    Date + "') as Redirects, " +
    " RowNum = ROW_NUMBER() OVER (ORDER BY Websites.ID) " +
    " FROM Websites " +
    " INNER JOIN Users ON Websites.UserID = Users.Id " +
    " Where Websites.Enabled = 1" +
    " GROUP BY Websites.Title, Websites.Description, Websites.Url, Websites.BannerURL , Users.Username, Websites.Id" +
    ") as Table1 " +
    " WHERE RowNum > " + number + " And RowNum <= " + amount + "" +
    " ORDER BY RowNum DESC"
    ;

您已经通过 RowNum 准备好有序数据，因此您不需要在子查询中使用 TOP 或 ORDER，只需将顺序应用于在最终 where 子句之后出现的被选中的行。

【讨论】：

谢谢，如果我想通过子查询订购：TotalVotes？
您可以在子查询完成后使用我介绍的 where 子句位置按任何列排序。但是，请记住您的行选择是基于特定顺序的，因此如果您更改显示顺序，您还需要更改 RowNum 的计算方式。

【解决方案2】：

注释掉 ORDER BY Websites.Id DESC。 & 使用 order by desc this in

 RowNum = ROW_NUMBER() OVER (ORDER BY Websites.ID Desc)

或在子查询中使用它。（上面没有评论）

SELECT top 100 percent

【讨论】：