Question

I am joining a table to an in memory list and wanting to create an anonymous type from the results. I have joined the 2 data sources together ok, but I’m not sure of the syntax required to use a property from the in memory list in the anonymous type.

Here’s my code

        public DataKeys(IEnumerable<Element> elements)
    {
        var defsource = new DefinitionSource();
        var items = from def in defsource.Definitions
                    where elements.Select(el=> el.Value).Contains(def.Name)                        
                    select new { def.Key };
        ...

    }

(Obviously “elements” is an in-memory list of element and “DefinitionSource” is a wrapper around a table.) This works fine, but as you can see there is no property from the in-memory list of elements. I’ve tried this

      var items = from def in defsource.Definitions
                  where elements.Select(el=> el.Value).Contains(def.Name)  
                  from el in elements
                  where el.Value.Equals(def.Name)
                  select new { el.NodeType, def.Key };

but at run time it gens a “{“Local sequence cannot be used in LINQ to SQL implementations of query operators except the Contains operator.”}”

So what is the syntax I need to do this?

Many thx IA

Simon

Answer 1

This might help:

var def=defsource.Definitions
                    .Where(a=>elements.Select(el=>el.Value).Contains(a.Name))
                    .ToList();
var items = from d in def
          from el in elements
            .Where(a=>a.Value==d.Name)
                  select new { el.NodeType, d.Key };