CODEWITHSUNDEEP
c#foreachwhile-loop
user2561466
user2561466

Reputation: 3

How to use foreach loops with while-loops

I have a while loop that continues to pull data from a query until the query returns no more results, within this the for each loop populates each returned data into an xml file. The query has a limit of 500 results per query so I wanted to return 500 results populate them and query again for the next 500 until the query return code < 1 (no results)

I am tracking the id and using this in the query to get the logic, however once the first 500 results return the loop does not get the next 500.

What I am doing wrong?

code:

bool is_finished = false;
while (is_finished == false)
{
    string current_id = "0";
    sb.Append("<queryxml><entity>Account</entity><query><field>AccountNumber<expression op='greaterthan'>" + current_id + "</expression></field></query></queryxml>").Append(System.Environment.NewLine);
    var r = client.query(at_integrations, sb.ToString());
    if (r.ReturnCode == 1)
    {

        foreach (var item in r.EntityResults) // max EntityResults 500 per query
        {
            Account acct = (Account)item;
            //create xml file with the results
            current_id = acct.id.ToString();
        }
    }
    else
    {
        is_finished = true;
    }
}

Upvotes: 1

Views: 160

Answers (1)

Rudi Visser
Rudi Visser

Reputation: 22029

You have the definition of current_id within your loop, each iteration it will reset it to zero.

You should debug this, you could quite easily add Debug.WriteLine(sb); to see the contents and you'd see that it would always return the same (note that current_id is always 0):

<queryxml><entity>Account</entity><query><field>AccountNumber<expression op='greaterthan'>0</expression></field></query></queryxml>

Here's updated code, which simply moves the definition of current_id out of the loop, so that it can be updated and the value will stick.

bool is_finished = false;
string current_id = "0";
while (is_finished == false)
{
    sb.Append("<queryxml><entity>Account</entity><query><field>AccountNumber<expression op='greaterthan'>" + current_id + "</expression></field></query></queryxml>").Append(System.Environment.NewLine);
    var r = client.query(at_integrations, sb.ToString());
<snip>

Upvotes: 1

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