Linq與加入羣組

Question

如何在linq中編寫以下sql連接？

select Campaign.CampaignName, COUNT(*) as total 
from Campaign join CampaignAsset 
on CampaignAsset.CampaignId=Campaign.CampaignId 
where Campaign.UserProfileId=65 
Group By Campaign.CampaignName 

Answer 1

試試這個：

 YourDatabaseName dataContext = new YourDatabaseName(); 

var result = from c in dataContext.Campaign 
       join ca in dataContext.CampaignAsset on c.CampaignId equals ca.CampaignId into j1 
       from j2 in j1.DefaultIfEmpty() 
       where c.UserProfileId = 65     
       group j2 by c.CampaignName into grouped 
       select new { CampaignName = grouped.Key, Count = grouped.Count() };