Modify List within foreach loop with value from another list

Question

I am looping through a list and insert these values into another object. However I have another list and if inv.id and inv.name match I need to update the amount and qty with the values from the other list. What is best approach?

//loop through Invoices

 foreach (invoice inv in list1)
 {

//if id and name match my other list(list2) I need to replace inv.amount and inv.qty with the values from the other list (list2.amount, list2.qty)

InsertAdditionalInvoice(inv.ID, inv.name, inv.address, inv.lot, inv.order,   
inv.invoiceid, inv.amount, inv.qty);

 }
}

it is not updating the values in the first list. I have a method that returns the list then call it with following code:

var list2 = GetInivoice2();

I then call this list as follows in the foreach loop:

var listtmp = list2.FirstOrDefault(o => o.ID == inv.ID && o.name == inv.name );
if (listtmp != null)
{
req.Quantity = Convert.ToDouble(listtmp.Quantity);

here is list method that returns my list(names are different):

public List GetInvoice2() {

        List<inv2> inv2s = new List<inv2>();
        Database db = DatabaseFactory.CreateDatabase("tmp");


        DbCommand cmd = db.GetStoredProcCommand("getinv2");


        using (IDataReader reader = db.ExecuteReader(cmd))
        {
            while (reader.Read())
            {
                inv2.Add(new inv2
                {
                    InvoiceID = Convert.ToInt32(reader["InvoiceID"]),
                    InvoiceName = reader["InvoiceName"].ToString(),
                    Quantity = Convert.ToDecimal(reader["Quantity"]),

                });
            }
        }
        return inv2;

    }

Your question is very unclear. Well, if you need to find some values in another list, then search them! — Moha Dehghan
– Moha Dehghan, Commented Nov 21, 2013 at 5:47

har07 · Accepted Answer · 2013-11-21 06:01:10Z

1

This one will work i think

//if id and name match my other list(list2) I need to replace inv.amount and inv.qty with the values from the other list (list2.amount, list2.qty)
var q = list2.FirstOrDefault(o => o.ID == inv.ID && o.name == inv.name);
if (q != null)
{
    inv.amount = q.amount;
    inv.qty = q.qty;
}

Add above codes before calling InsertAdditionalInvoice. I'm not sure if this is the best approach or not, but i usually do it this way.

edited Nov 21, 2013 at 6:01

answered Nov 21, 2013 at 5:49

har07

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3 Comments

kman Over a year ago

or just: var q = list2.FirstOrDefault(o => o.ID == inv.ID && o.name == inv.name);

mick Over a year ago

it is not updating the values in the first list. I have a method that returns the list then call it with following code: var list2 = GetInivoice2(); I then call this list as follows in the foreach loop: var listtmp = list.FirstOrDefault(o => o.ID == inv.ID && o.name == inv.name ); if (listtmp != null) { req.Quantity = Convert.ToDouble(listtmp.Quantity); }

har07 Over a year ago

if you set breakpoint inside if(q != null), is your program ever hit the breakpoint?

Kirill Bestemyanov · Accepted Answer · 2013-11-21 05:52:54Z

0

Straight solution:

var l2value=list2.FirstOrDefault(l=>l.id==inv.id)
if(l2value!=null){
    inv.amount=l2value.amount;
    Inv.qty=l2value.qty;
}

answered Nov 21, 2013 at 5:52

Kirill Bestemyanov

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