Creating multiple array using a foreach loop and a select statement

Question

I have a database that I call select all of its contents of a table. It has 18000+ items. I have a method uses a web service that can have an array of up to ten element pass into it. Right now I am doing item by item instead of by an array. I want to create an array of ten and then call the function. I could make an array of ten and then call the function be what is I have an extra three records?

public static void Main()
{
    inventoryBLL inv = new inventoryBLL();
    DataSet1.sDataTable dtsku = inv.SelectEverything();
    foreach (DataSet1.Row row in dtsku)
    {
        webservicefunction(row.item);
    }
}

My question is how would I transform this?

Andrey Kamaev · Accepted Answer · 2011-08-29 20:56:18Z

1

Generic solution of your problem could look like this:

static class LinqHelper
{
    public static IEnumerable<T[]> SplitIntoGroups<T>(this IEnumerable<T> items, int N)
    {
        if (items == null || N < 1)
            yield break;

        T[] group = new T[N];
        int size = 0;
        var iter = items.GetEnumerator();

        while (iter.MoveNext())
        {
            group[size++] = iter.Current;
            if (size == N)
            {
                yield return group;
                size = 0;
                group = new T[N];
            }
        }
        if (size > 0)
            yield return group.Take(size).ToArray();
    }
}

So your Main function become

public static void Main()
{
    inventoryBLL inv = new inventoryBLL();
    DataSet1.sDataTable dtsku = inv.SelectEverything();
    foreach (var items in dtsku.Select(r => r.item).SplitIntoGroups(10))
    {
        webservicefunction(items);
    }
}

answered Aug 29, 2011 at 20:56

Andrey Kamaev

30.2k6 gold badges100 silver badges89 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Joe Tyman Over a year ago

I get two errors 1 Cannot convert lambda expersion to type 'string' because it is not a delegate type, 2 Does not contain for 'item'.

Andrey Kamaev Over a year ago

Please most more details about your code. As minimum provide DataSet1.sDataTable and DataSet1.Row class declarations and exact signature of your webservicefunction. Otherwise it is difficult to say why you have such errors.

rtalbot · Accepted Answer · 2011-08-29 21:04:38Z

0

var taken = 0;
var takecount = 10;
while(list.Count() >= taken)
{
     callWebService(list.Skip(taken).Take(takecount));
     taken += takecount;
}

Generic Extension Method version:

public static void AtATime<T>(this IEnumerable<T> list, int eachTime, Action<IEnumerable<T>> action)
{
      var taken = 0;
      while(list.Count() >= taken)
      {
           action(list.Skip(taken).Take(eachTime));
           taken += eachTime;    
      }
}

Usage:

inv.SelectEverything().AtATime<Row>(10, webservicefunction);

edited Aug 29, 2011 at 21:04

answered Aug 29, 2011 at 20:33

rtalbot

1,64510 silver badges13 bronze badges

5 Comments

Joe Tyman Over a year ago

this is really confusing because it is seemingly in a vacuum.

rtalbot Over a year ago

I don't understand your comment. The code(pseudocode?) provided will take a list and while there are items to process it will send them 10 at a time to callWebService. Isn't that what you want?

Magnus Over a year ago

This works out, but not optimal: skip needs to start from the beginning in each call until it reaches taken.

Magnus Over a year ago

And Count() needs to iterate the complete collection

rtalbot Over a year ago

Yeah, good points, but it's pretty and OP doesn't specify any performance constraints.

Collectives™ on Stack Overflow

Creating multiple array using a foreach loop and a select statement

2 Answers 2

2 Comments

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related