Linq to update a collection with values from another collection?

Question

I have IQueryable baseList

and List someData

What I want to do is update attributes in some

Answer 1

To pair elements in the two lists you can use a LINQ join:

var pairs = from d in someData
            join b in baseList.AsEnumerable()
                on d.someCode equals b.myCode
            select new { b, d };

This will give you an enumeration of each item in someData paired with its counterpart in baseList. From there, you can concatenate in a loop:

foreach(var pair in pairs)
    pair.b.SomeData += pair.d.DataIWantToConcantenate;

If you really meant set concatenation rather than +=, take a look at LINQ's Union, Intersect or Except methods.