CODEWITHSUNDEEP
c#linq-to-sql
JamesBB
JamesBB

Reputation: 183

Choose type in foreach loop

in my program, I use 4 stored procedures, depending on fields that were selected in the form.

ctx = new DataClassesDataContext();
items = (from prjs in ctx.sp_Select_Stuknummers(prjnr) select prjs).ToList();

or

ctx = new DataClassesDataContext();
items = (from prjs in ctx.sp_Select_Stuknummers_Scanner(prjnr, scanner) select prjs).ToList();

and so on ...

I use LINQ to SQL, and for each of these 4 queries, I have a different result class:

sp_Select_StuknummersResult
sp_Select_Stuknummers_ScannerResult
sp_Select_Stuknummers_Scanner_WPSResult
sp_Select_Stuknummers_StuknummerResult

they all have the same fields and definitions.

Now, when I iterate the result:

foreach (sp_Select_StuknummersResult x in items)
        {
            WPSitems ding = new WPSitems();
            ding.ID = x.ID;
            ding.Naam = x.Naam;
        ......

        }

I need to pass the type to use (in this example: sp_Select_StuknummersResult )

Is there a way to either A. easily convert to a new type, so that one can be used every time or B. dynamically set the type in the foreach loop ?

maybe there is even a C that I am not aware of... Any help is highly appreciated !

Upvotes: 0

Views: 134

Answers (3)

jeroenh
jeroenh

Reputation: 26792

By default, L2S auto-generates a separate type for each individual stored procedure. However, you can easily change that return type in the Linq-2-Sql Designer.

In the designer, click on the stored procedure. In the Properties window, there's an entry 'Return Type': change it from 'Auto-generated type' to the type you want.

If the stored procedure returns rows from an already mapped table, select that type in the drop-down. If not, you can manually add a class to the designer and configure that type to be returned from the stored procedure.

example

Upvotes: 1

Bojan B
Bojan B

Reputation: 2111

If I understand your problem correctly this might help you out:

1.) Create an interface for the result classes (e.g.) I_SP: 

sp_Select_StuknummersResult
sp_Select_Stuknummers_ScannerResult
sp_Select_Stuknummers_Scanner_WPSResult
sp_Select_Stuknummers_StuknummerResult
  • add common variables and methods that you need into that interface.

2.) Make sure your items is List<I_SP>

3.) Create a generic method for your foreach loop

public void MyMethod<T>(List<I_SP> items) where T:I_SP {
  foreach (var x in items.OfType<T>)
  {
    WPSitems ding = new WPSitems();
    ding.ID = x.ID;
    ding.Naam = x.Naam;
    ......
  }
}

4.) Then just call this like this: 

MyMethod<*sp_Select_StuknummersResult result class*>(items);

Hope it's clear enough.

Upvotes: 0

MrGudim
MrGudim

Reputation: 1

You can do this using generics/reflection.

public static WPSitems MapObjectWithIdenticalProperties<T>(T itemOfUnknownType) where T : new() 
    {
        var inputType = typeof(T);

        var outputType = typeof(WPSitems);

            var outputItem = new WPSitems();
            foreach (var inputProperty in inputType.GetProperties())
            {
                var matchingOutputProperty = outputType.GetProperties().FirstOrDefault(x => x.Name == inputProperty.Name);
                if(matchingOutputProperty != null)
                    matchingOutputProperty.SetValue(outputItem, inputProperty.GetValue(itemOfUnknownType));
            }
        return outputItem;
    }

The function above can be called like this:

var items = GetYourDataThatCanBeDifferentTypes();
var mappedItems = new List<WPSitems>();

foreach(var item in items)
    mappedItems.add(MapObjectWithIdenticalProperties(item));

Upvotes: 0

Related Questions