I would try to select your data into an anonymous type in your linq query, perform the union, and add your criteria.
var listExamen = context.Examen
.Select(x => new { x.Prop1, x.Prop2, ... }); // Add properties
var listExploracion = context.Exploraction
.Select(x => new { x.Prop1, x.Prop2, ... }); // Add identical properties
var listCombined = listExamen.Concat(listExploracion);
var whereAdded = listCombines
.Where(x => x.Prop1 == someValue);
var result = whereAdded
.Skip(skipCount)
.Take(takeCount)
.ToList();
Note: I have no idea if you can use Common Table Expressions (the SQL necessity for skip/take) in combination with a Union-query
Note: I've changed the methods used to create the expressions, since I do not know your methods (Project
, To
)
So I think the solution is not to cast to a specific type, but to an anonymous type, since that probably can be translated to SQL.
Warning: didn't test it