Xtykutl

I just saw this piece of code and asked myself how it can be improved to reduce the amount of queries. Tried a few LINQ statements but could not find an answer.

    public static Dictionary<string, Computer> GetComputer(IEnumerable<string> workStations)

    {

        var dict = new Dictionary<string, Computer>();

        using (var db = new ComputerContext())

        {

                foreach (var workStation in workStations)

                {

                    var t = db.Computers.FirstOrDefault(o => o.Id.Equals(workStation));



                    if (!dict.ContainsKey(workStation))

                    {

                        dict.Add(workStation, t);

                    }

                }



                return dict;

        }

    }

When trying someting like this:

var computers = db.Computers.Where(x => workStations.Select(y => y).Equals(x.Id)).ToList();



foreach (var computer in computers)

{

    if (!dict.ContainsKey(computer.Id))

    {

        dict.Add(computer.Id, computer);

    }

}

Intellisense is telling me "Suspicious comparison: there is no type in the solution which is inherited from both

'System.Collections.Generic.IEnumerable' and 'string'" which
leds to an Exception "Cannot compare elements of type
'System.Collections.Generic.IEnumerable`1[[System.String, mscorlib,
Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]'.
Only primitive types, enumeration types and entity types are
supported."

The problem is in your query. Try this code:

var computers = db.Computers.Where(x => workStations.Any(y => y.Equals(x.Id)).ToList();



foreach (var computer in computers)

{

    if (!dict.ContainsKey(computer.Id))

    {

        dict.Add(computer.Id, computer);

    }

}