I need to return an IEnumerable of a dynamically created Dictionary.
pseudo code:
var x = from u in Users
select new dictionary<string, string>{
Add("Name",u.Name),
Add("LastName",u.LastName)
}
I've been trying many ways to get the pseudo code example above but no success...
I would really appreciate your help.
var x = from u in Users
select new Dictionary<string, string> {
{ "Name", u.Name },
{ "LastName", u.LastName }
};
from u in Users.AsEnumerable() as Users might be IQueryable and it's trying to convert the whole LINQ statement in SQL script.The "Unrecognized expression node" error you're getting is because LINQ to SQL is failing to turn the dictionary-related code into SQL. You can use AsEnumerable() to make the compiler use LINQ to Objects instead:
var x = from u in Users.AsEnumerable()
select new Dictionary<string, string> {
{ "Name", u.Name },
{ "LastName", u.LastName }
};
That is poor use of a dictionary - you're only using it as a property bag, and create as many dictionaries as users.
A better use of the language would be creating your own User class with these properties and use that:
public class User
{
public string Name { get; set; }
public string LastName { get; set; }
}
And the query:
var users = Users.Select(u => new User
{
Name = u.Name,
LastName = u.LastName
});
If you'll only use the collection whiting your method, another option is to create an anonymous class:
var users = Users.Select(u => new { Name = u.Name, LastName = u.LastName });
"Hello [[Name]], You've ordered [[ItemsCount]] items at $[[ItemsPrice]]. Please see <a href='[[TermsURL]]'>Terms of Use</a>". I had a OrderContext class with User, Order, etc, and it can replace tokens with the appropriate string. This is probably better than turning each and every entity to a dictionary.Conversion method:
public Dictionary<string, string> ToPropertyDictionary(User theUser)
{
Dictionary<string, string> result = new Dictionary<string, string>();
result.Add("Name", theUser.Name);
result.Add("LastName", theUser.Name);
return result;
}
Called by:
IEnumerable<Dictionary<string, string>> x =
from u in Users.AsEnumerable() //ensure local execution by using AsEnumerable
select ToPropertyDictionary(u);
User.Select(u => u.ToPropertyDictionary())
IEnumerable<Dictionary<string,string>>seems a bit odd, specially when you have to hardcode all elements.