使用NHibernate选择第n行 [英] Select every nth row with NHibernate

问题描述

您将如何使用NHibernate QueryOver，HQL或Criteria实现选择第n行的查询?

How would you implement a query that selects every nth row, with NHibernate QueryOver, HQL or Criteria?

当前，我使用以下T-SQL查询:

Currently I use the following T-SQL query:

SELECT * FROM (
    SELECT *, ROW_NUMBER() OVER (ORDER BY Id) AS [Row]
    FROM [TABLE_NAME]
) x WHERE (x.[Row] % 100) = 0

(感谢 Marc Gravell )

推荐答案

您是否考虑过在交叉联接中使用索引表的解决方案?我的意思是，您的表中的行数与您认为的需要的行数一样，每行的索引列整数从1-n开始.这可以在主数据库中，也许旁边还有一个日期列-这种方法的实用性令人惊讶.然后查询看起来像

Have you considered the solution of using an indexing table in a cross join? What I mean is that you have a table with as many rows as you think you will need with an indexed column of integers going from 1-n in each row. This can be in a master database perhaps with a date column beside it - its amazing how useful this method is. The query would then look like

SELECT * FROM (
    SELECT *, ROW_NUMBER() OVER (ORDER BY Id) AS [Row]
    FROM [TABLE_NAME]
) x INNER JOIN [Index_Table] i ON i.Id*100=x.[Row]

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