左外连接3表linq到sql

Question

我试图写一个查询linq在哪里我加入3表格和填充字符串“ANY”的空值，但这不是发生需要一些帮助，请我新在这。

我试图做这样的事情...

var results = from user in allusers 
       join building in allbuildings where building.buildingid equals user.buildingid 
       into BuildingAndUsers.FirstorDefault(new allbuildings{BuildingName="ANY" BuildingID=0}) 
       from blah in BuildingAndUsers 
       join Site in AllSites where .... 

Answer 1

喜欢的东西：

var results = 
     from user in allusers 
     join building in allbuildings on building.buildingid equals user.buildingid 
      into BuildingAndUsers 
     from buildingAndUser in BuildingAndUsers.DefaultIfEmpty(new allbuildings { BuildingName="ANY", BuildingID=0 }) 
     join Site in AllSites on .... 
      into BuildingAndUsersAndSites 
     from buildingAndUsersAndSite in BuildingAndUsersAndSites.DefaultIfEmpty() 
     select ...