从SQL查询转换为Linq查询

Question

有人可以将此查询更改为Linq

SELECT Causes.CauseTitle，COUNT（Calender.CauseID）AS NumberOfOccurance FROM Calender LEFT JOIN原因 ON Calender.CauseID = Causes.CauseID GROUP BY CauseTitle;

提前致谢

Answer 1

请尝试以下linq查询。我没试过这个。如果有任何问题，请告诉我。

from cal in Calender
join cas in Causes on cal.CauseID equals cas.CauseID into j1
from j2 in j1.DefaultIfEmpty()
group j2 by cas.CauseTitle into grouped
select new { CauseTitle = grouped.Key, NumberOfOccurance = grouped.Count(t=>t.CauseID != null) }