c# - EF Linq to Entities Query with groupby sum 和 min

Question

我正在尝试使 Linq to Entities Query 正常工作，但我无法弄明白。

这是我的 SQL 查询，运行良好:

SELECT SUM(ca.PointValue) as Points, ua.UserFBID, MIN(ua.[Date]) as FirstDate
  FROM [LeaderOfNow].[dbo].[QuestionAnswer] ca
  inner join [LeaderOfNow].[dbo].[LONUserAnswers] ua
  on ca.Id = ua.AnswerId
  group by ua.UserFBID
  order by Points desc, FirstDate asc

到目前为止我最好的尝试是:

            var leaders = db.LONUserAnswers
                .GroupBy(a => a.UserFBID)
                .Select(a =>
                new 
                {
                    FBID = a.Key,
                    CurrentPoints = a.Select(v => v.QuestionAnswer.PointValue).Sum(),
                    FirstAnswered = a.Min(v => v.Date)
                })
.OrderByDescending(a => a.CurrentPoints)
                .OrderBy(a => a.FirstAnswered)
                .Take(10)
                .ToList();

然而，这会导致 sql 困惑，并且只尊重第一个顺序而不是第二个顺序，这是我需要工作的。关于我做错了什么的任何建议？感谢您的帮助。

Answer 1

当您链接 OrderBy-Functions 时，您必须为后者使用 ThenBy() 或 ThenDescendingBy()。