如何使用Linq查询存储过程对象

Question

Say I got this situation: I have to filter one of my entities with data which I get from an stored procedure:

var results = from c in db.Customer
join p in db.GetSPResults() on c.Id equals p.Id
select c;

on my Context class I got this:

public ObjectResult<Example> GetSPResults()
{
    return (this as IObjectContextAdapter).ObjectContext.ExecuteFunction<Example>("Proc_Example");
}

So far I run into 2 problems:

1. I get an InvalidOperationException when code strikes the ExcecuteFunction line:

   The FunctionImport 'xxx' could not be found in the container 'xxx' .

2. Assuming you guys can help me to solve that problem, would it be possible to query that way? Using those stored procedure results like a context entity? I think EF won't allow that cause it's not an entity, nor a "Constant Value".

I'm using EF 4.3.

Answer 1

instead of calling your procedure like that by name as string you can import it in your entity model then you can have a type safe / strongly typed method call directly on your DbContext.

basically you need to execute a function import, see here for an example: Using stored procedures with Entity Framework

Update: for POCO / Code first, see here: EF Code-First - Mapping stored procedures