I'm trying to improve performance of a web application by caching a query.
public static Func<myEntity, List<HASHDuplicates>, IQueryable<FormResponse>> CompiledDuplicatedResponses =
CompiledQuery.Compile<myEntity, List<HASHDuplicates>, IQueryable<FormResponse>>(
(db, hashes) => from r in db.FormResponse
from h in db.IndexHASHes
from d in hashes
where r.id == h.FormResponseID && h.IndexHASHString == d.hash
select r);
The error I receive is at compile time:
The type 'myEntity' cannot be used as type parameter 'TArg0' in the generic type or method 'System.Data.Entity.Core.Objects.CompiledQuery.Compile(System.Linq.Expressions.Expression>)'. There is no implicit reference conversion from 'myEntity' to 'System.Data.Entity.Core.Objects.ObjectContext'.
I'm using EF6
Ok it seems that in EF5 and greater the queries are automatically compiled and there is no need to compile them. The ObjectContext is not used anymore, and we have now DbContext: Compiled Query no implicit reference conversion to ObjectContext
Another interesting post on Compiled Query: http://blog.codinghorror.com/compiled-or-bust/
来源:https://stackoverflow.com/questions/26191721/entity-framework-6-compiled-linq-query