类型推断呼叫失败“的SelectMany”

Question

我有这样的LINQ查询：

 var businessAffiliates = from b in context.Businesses 
           from ba in b.BusinessOfficers 
           from p in ba.Person          
           select b; 

，但我收到此错误：

An expression of type 'myproj.Models.Person' is not allowed in a subsequent from clause in a query expression with source type 'System.Linq.IQueryable'. Type inference failed in the call to 'SelectMany'.

Answer 1

它看起来像ba.Person它的单个对象，但from子句需要一系列对象。 如果你用let p = ba.Person替换该行，那么它会工作。但我想知道为什么你需要这些额外的from子句。