Sample: Use FetchXML with a paging cookie

 

Applies To: Dynamics 365 (online), Dynamics 365 (on-premises), Dynamics CRM 2016, Dynamics CRM Online

This sample code is for Microsoft Dynamics 365 (online & on-premises). Download the Microsoft Dynamics CRM SDK package. It can be found in the following location in the download package:

SampleCode\CS\GeneralProgramming\Queries\FetchPagingWithCookie.cs

Requirements

For more information about the requirements for running the sample code provided in this SDK, see Use the sample and helper code.

Example

This sample shows how to use the paging cookie in a FetchXML query to retrieve successive pages of query results. It uses the IOrganizationService. RetrieveMultiple method.


using System;
using System.ServiceModel;
using System.ServiceModel.Description;
using System.Collections.Generic;
using System.Text;
using System.Xml;
using System.IO;

// These namespaces are found in the Microsoft.Xrm.Sdk.dll assembly
// found in the SDK\bin folder.
using Microsoft.Xrm.Sdk;
using Microsoft.Xrm.Sdk.Client;
using Microsoft.Xrm.Sdk.Query;
using Microsoft.Xrm.Sdk.Discovery;

// This namespace is found in Microsoft.Crm.Sdk.Proxy.dll assembly
// found in the SDK\bin folder.
using Microsoft.Crm.Sdk.Messages;
using Microsoft.Xrm.Sdk.Messages;


namespace Microsoft.Crm.Sdk.Samples
{
    /// <summary>
    /// Demonstrates how to use the Fetch XML method with a paging
    /// cookie to retrieve a batch of records.
    /// If you want to run this sample repeatedly, you have the option to 
    /// delete all the records created at the end of execution.
    /// </summary>
    class FetchPagingWithCookie
    {
        #region Class Level Members

        /// <summary>
        /// Stores the organization service proxy.
        /// </summary>
        private OrganizationServiceProxy _serviceProxy;
        private IOrganizationService _service;

        // Define the IDs needed for this sample.
        public Guid _parentAccountId;
        public Guid[] _childAccountIds;

        #endregion Class Level Members

        #region How To Sample Code
        /// <summary>
        /// Create and configure the organization service proxy.
        /// Create a parent account record and subsequent 10 child account records.
        /// Retrieve batch of records using RetrieveMultiple message with paging cookie.
        /// Optionally delete any entity records that were created for this sample.
        /// </summary>
        /// <param name="serverConfig">Contains server connection information.</param>
        /// <param name="promptForDelete">When True, the user will be prompted to delete all
        /// created entities.</param>
        public void Run(ServerConnection.Configuration serverConfig, bool promptForDelete)
        {
            try
            {

                // Connect to the Organization service. 
                // The using statement assures that the service proxy will be properly disposed.
                using (_serviceProxy = new OrganizationServiceProxy(serverConfig.OrganizationUri, serverConfig.HomeRealmUri,serverConfig.Credentials, serverConfig.DeviceCredentials))
                {
                    // This statement is required to enable early-bound type support.
                    _serviceProxy.EnableProxyTypes();

                    _service = (IOrganizationService)_serviceProxy;

                    // Call the method to create any data that this sample requires.
                    CreateRequiredRecords();

                    // Define the fetch attributes.
                    // Set the number of records per page to retrieve.
                    int fetchCount = 3;
                    // Initialize the page number.
                    int pageNumber = 1;
                    // Initialize the number of records.
                    int recordCount = 0;
                    // Specify the current paging cookie. For retrieving the first page, 
                    // pagingCookie should be null.
                    string pagingCookie = null;

                    // Create the FetchXml string for retrieving all child accounts to a parent account.
                    // This fetch query is using 1 placeholder to specify the parent account id 
                    // for filtering out required accounts. Filter query is optional.
                    // Fetch query also includes optional order criteria that, in this case, is used 
                    // to order the results in ascending order on the name data column.
                    string fetchXml = string.Format(@"<fetch version='1.0' 
                                                    mapping='logical' 
                                                    output-format='xml-platform'>
                                                    <entity name='account'>
                                                        <attribute name='name' />
                                                        <attribute name='emailaddress1' />
                                                        <order attribute='name' descending='false'/>
                                                        <filter type='and'>
                                                            <condition attribute='parentaccountid' 
                                                                operator='eq' value='{0}' uiname='' uitype='' />
                                                        </filter>
                                                    </entity>
                                                </fetch>",
                                                    _parentAccountId);

                    Console.WriteLine("Retrieving data in pages\n"); 
                    Console.WriteLine("#\tAccount Name\t\t\tEmail Address");

                    while (true)
                    {
                        // Build fetchXml string with the placeholders.
                        string xml = CreateXml(fetchXml, pagingCookie, pageNumber, fetchCount);

                        // Excute the fetch query and get the xml result.
                        RetrieveMultipleRequest fetchRequest1 = new RetrieveMultipleRequest
                        {
                            Query = new FetchExpression(xml)
                        };

                        EntityCollection returnCollection = ((RetrieveMultipleResponse)_service.Execute(fetchRequest1)).EntityCollection;

                        foreach (var c in returnCollection.Entities)
                        {
                            System.Console.WriteLine("{0}.\t{1}\t\t{2}", ++recordCount, c.Attributes["name"], c.Attributes["emailaddress1"] );
                        }                        

                        // Check for morerecords, if it returns 1.
                        if (returnCollection.MoreRecords)
                        {
                            Console.WriteLine("\n****************\nPage number {0}\n****************", pageNumber);
                            Console.WriteLine("#\tAccount Name\t\t\tEmail Address");

                            // Increment the page number to retrieve the next page.
                            pageNumber++;

                            // Set the paging cookie to the paging cookie returned from current results.                            
                            pagingCookie = returnCollection.PagingCookie;
                        }
                        else
                        {
                            // If no more records in the result nodes, exit the loop.
                            break;
                        }
                    }

                    DeleteRequiredRecords(promptForDelete);
                }
            }
            // Catch any service fault exceptions that Microsoft Dynamics CRM throws.
            catch (FaultException<Microsoft.Xrm.Sdk.OrganizationServiceFault>)
            {
                // You can handle an exception here or pass it back to the calling method.
                throw;
            }
            return;
        }


        public string ExtractNodeValue(XmlNode parentNode, string name)
        {
            XmlNode childNode = parentNode.SelectSingleNode(name);

            if (null == childNode)
            {
                return null;
            }
            return childNode.InnerText;
        }

        public string ExtractAttribute(XmlDocument doc, string name)
        {
            XmlAttributeCollection attrs = doc.DocumentElement.Attributes;
            XmlAttribute attr = (XmlAttribute)attrs.GetNamedItem(name);
            if (null == attr)
            {
                return null;
            }
            return attr.Value;
        }

        public string CreateXml(string xml, string cookie, int page, int count)
        {
            StringReader stringReader = new StringReader(xml);
            XmlTextReader reader = new XmlTextReader(stringReader);

            // Load document
            XmlDocument doc = new XmlDocument();
            doc.Load(reader);

            return CreateXml(doc, cookie, page, count);
        }

        public string CreateXml(XmlDocument doc, string cookie, int page, int count)
        {
            XmlAttributeCollection attrs = doc.DocumentElement.Attributes;

            if (cookie != null)
            {
                XmlAttribute pagingAttr = doc.CreateAttribute("paging-cookie");
                pagingAttr.Value = cookie;
                attrs.Append(pagingAttr);
            }

            XmlAttribute pageAttr = doc.CreateAttribute("page");
            pageAttr.Value = System.Convert.ToString(page);
            attrs.Append(pageAttr);

            XmlAttribute countAttr = doc.CreateAttribute("count");
            countAttr.Value = System.Convert.ToString(count);
            attrs.Append(countAttr);

            StringBuilder sb = new StringBuilder(1024);
            StringWriter stringWriter = new StringWriter(sb);

            XmlTextWriter writer = new XmlTextWriter(stringWriter);
            doc.WriteTo(writer);
            writer.Close();

            return sb.ToString();
        }

        /// <summary>
        /// This method creates any entity records that this sample requires.
        /// Create a parent account record.
        /// Create 10 child accounts to the parent account record.
        /// </summary>
        public void CreateRequiredRecords()
        {
            // Instantiate a account entity record and set its property values.
            // See the Entity Metadata topic in the SDK documentation
            // to determine which attributes must be set for each entity.
            // Create the parent account.
            Account parentAccount = new Account
            {
                Name = "Root Test Account",
                EMailAddress1 = "root@root.com"
            };


            _parentAccountId = _service.Create(parentAccount);

            // Create 10 child accounts.
            _childAccountIds = new Guid[10]; 
            int count = 1;
            while (true)
            {
                Account childAccount = new Account
                {
                    Name = "Child Test Account " + count.ToString(),
                    EMailAddress1 = "child" + count.ToString() + "@root.com",
                    EMailAddress2 = "same@root.com",
                    ParentAccountId = new EntityReference(Account.EntityLogicalName, _parentAccountId)
                };

                _childAccountIds[count - 1] = _service.Create(childAccount);

                // Jump out of the loop after creating 10 child accounts.
                if (count == 10)
                    break;
                // Increment the count.
                count++;
            }            
            return;
        }

        /// <summary>
        /// Deletes any entity records that were created for this sample.
        /// <param name="prompt">Indicates whether to prompt the user to delete the records created in this sample.</param>
        /// </summary>
        public void DeleteRequiredRecords(bool prompt)
        {
            bool deleteRecords = true;

            if (prompt)
            {
                Console.WriteLine("\nDo you want these entity records deleted? (y/n)");
                String answer = Console.ReadLine();

                deleteRecords = (answer.StartsWith("y") || answer.StartsWith("Y"));
            }

            if (deleteRecords)
            {
                // Remove the test parent account.
                _service.Delete(Account.EntityLogicalName, _parentAccountId);

                // Remove 10 test child accounts.
                int deleteCount = 0;
                while (deleteCount < 10)
                {
                    _service.Delete(Account.EntityLogicalName, _childAccountIds[deleteCount]);
                    ++deleteCount;
                }

                Console.WriteLine("Entity records have been deleted.");
            }
        }

        #endregion How To Sample Code

        #region Main

        /// <summary>
        /// Standard Main() method used by most SDK samples.
        /// </summary>
        /// <param name="args"></param>
        static public void Main(string[] args)
        {
            try
            {
                // Obtain the target organization's Web address and client logon 
                // credentials from the user.
                ServerConnection serverConnect = new ServerConnection();
                ServerConnection.Configuration config = serverConnect.GetServerConfiguration();

                FetchPagingWithCookie app = new FetchPagingWithCookie();
                app.Run(config, true);
            }
            catch (FaultException<Microsoft.Xrm.Sdk.OrganizationServiceFault> ex)
            {
                Console.WriteLine("The application terminated with an error.");
                Console.WriteLine("Timestamp: {0}", ex.Detail.Timestamp);
                Console.WriteLine("Code: {0}", ex.Detail.ErrorCode);
                Console.WriteLine("Message: {0}", ex.Detail.Message);
                Console.WriteLine("Plugin Trace: {0}", ex.Detail.TraceText);
                Console.WriteLine("Inner Fault: {0}",
                    null == ex.Detail.InnerFault ? "No Inner Fault" : "Has Inner Fault");
            }
            catch (System.TimeoutException ex)
            {
                Console.WriteLine("The application terminated with an error.");
                Console.WriteLine("Message: {0}", ex.Message);
                Console.WriteLine("Stack Trace: {0}", ex.StackTrace);
                Console.WriteLine("Inner Fault: {0}",
                    null == ex.InnerException.Message ? "No Inner Fault" : ex.InnerException.Message);
            }
            catch (System.Exception ex)
            {
                Console.WriteLine("The application terminated with an error.");
                Console.WriteLine(ex.Message);

                // Display the details of the inner exception.
                if (ex.InnerException != null)
                {
                    Console.WriteLine(ex.InnerException.Message);

                    FaultException<Microsoft.Xrm.Sdk.OrganizationServiceFault> fe = ex.InnerException
                        as FaultException<Microsoft.Xrm.Sdk.OrganizationServiceFault>;
                    if (fe != null)
                    {
                        Console.WriteLine("Timestamp: {0}", fe.Detail.Timestamp);
                        Console.WriteLine("Code: {0}", fe.Detail.ErrorCode);
                        Console.WriteLine("Message: {0}", fe.Detail.Message);
                        Console.WriteLine("Plugin Trace: {0}", fe.Detail.TraceText);
                        Console.WriteLine("Inner Fault: {0}",
                            null == fe.Detail.InnerFault ? "No Inner Fault" : "Has Inner Fault");
                    }
                }
            }
            // Additional exceptions to catch: SecurityTokenValidationException, ExpiredSecurityTokenException,
            // SecurityAccessDeniedException, MessageSecurityException, and SecurityNegotiationException.

            finally
            {
                Console.WriteLine("Press <Enter> to exit.");
                Console.ReadLine();
            }

        }
        #endregion Main

    }
}

See Also

IOrganizationService
RetrieveMultiple
Build queries with FetchXML
Sample: Convert queries between Fetch and QueryExpression
Helper code: ServerConnection class
Use FetchXML aggregation
Use FetchXML to construct a query

Microsoft Dynamics 365

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