creating one datatable from two

Question

I have two datatables with identical schemas, business partners and addresses. I'm trying to combine them in a specific format in order to import into another system.

Basically, I want the output to be as follows:

Business Partner
All associated addresses
Next business partner
All associated addresses

Here is the latest code I'm trying:

            var finalDt = BpDt.Clone();

            foreach(DataRow BpRow in BpDt.Rows)
            {
                finalDt.ImportRow(BpRow);

                foreach(DataRow AddressRow in AddressDt.Rows)
                {
                    if(Convert.ToString(BpRow["id"]).Equals(Convert.ToString(BpRow["id"])))
                    finalDt.ImportRow(AddressRow);
                }
            }

It seems to get caught in a infinite loop but I don't understand why. Is there a better way to approach this?

score 1 · Answer 1 · answered Jul 09 '15 at 16:56

1

Your approach to this is terrible. But if you insist on going down this road, this should work:

 var finalDt = BpDt.Clone();

            foreach(DataRow BpRow in BpDt.Rows)
            {
                finalDt.ImportRow(BpRow);

                foreach(DataRow AddressRow in AddressDt.Rows)
                {
                    if(Convert.ToString(BpRow["id"]).Equals(Convert.ToString(AddressRow["id"])))
                    finalDt.ImportRow(AddressRow);
                }
            }

answered Jul 09 '15 at 16:56

Unknown Coder

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Thanks for the help... What would be a better approach? – user2486993 Jul 09 '15 at 17:09
@user2486993 How about doing this in the database instead? This is a data issue, not a coding issue, per-se, so why not handle it server side with SQL? – Unknown Coder Jul 09 '15 at 17:10
I agree that it is a silly way of doing it... I'm not sure how to approach this problem via SQL but i will look into it – user2486993 Jul 09 '15 at 17:25

score 0 · Accepted Answer · edited May 23 '17 at 11:43

0

it seems like...

if(Convert.ToString(BpRow["id"]).Equals(Convert.ToString(BpRow["id"])))

will always be true. So you would just be inserting every AddressRow for each BpRow. Depending on your dataset size, this could be taking a really long time. Should the id comparison be this?

if(Convert.ToString(AddressRow["id"]).Equals(Convert.ToString(BpRow["id"])))

Conceptually this would be similar to a join on the id field.

A better approach might be to use LINQ. If you use the AsEnumerable() extension for DataTable you could query AddressDt using LINQ...

LINQ query on a DataTable

edited May 23 '17 at 11:43

Community

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1

answered Jul 09 '15 at 16:37

temarsden

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Answered first and correctly and got downvoted. Interesting. – temarsden Jul 09 '15 at 17:00
well i'm an idiot... you are right I'm basically trying to do a join and was comparing the wrong fields... luckily there are only about 10,000 records so it goes quick but I'll take a look at LINQ for future reference. Thanks! – user2486993 Jul 09 '15 at 17:07
It happens to everyone from time to time :) – temarsden Jul 09 '15 at 17:08
@temarsden To the Victor go the spoils :-) – Unknown Coder Jul 09 '15 at 17:14
@JimBeam Nice, I see what you did there ;-) – temarsden Jul 09 '15 at 17:15

creating one datatable from two

2 Answers2