Sample: Create a LINQ query

 

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\CreateALinqQuery.cs

Requirements

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

Demonstrates

This sample shows how to create simple .NET Language-Integrated Query (LINQ) queries. The following queries are demonstrated:

  • Retrieve all accounts that the calling user has access to.

  • Retrieve all accounts owned by the user who has read access rights to the accounts and where the last name of the user is not “Cannon.”

  • Return a count of all accounts that have a county specified in their addresses.

  • Return a count of states in which we have an account. This uses the distinct keyword that counts a state only once.

  • Return contacts where the city equals “Redmond” AND the first name is “Joe” OR “John.”

Example


using System;
using System.ServiceModel;
using System.Linq;
using System.Collections.Generic;

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

namespace Microsoft.Crm.Sdk.Samples
{
 /// <summary>
 /// Demonstrates how to do create basic LINQ queries against Microsoft Dynamics CRM
 /// records.</summary>
 /// <remarks>
 /// At run-time, you will be given the option to delete all the
 /// database records created by this program.</remarks>
 public class CreateALinqQuery
 {
  #region Class Level Members

  private Dictionary<Guid, String> _recordIds = new Dictionary<Guid, String>();
  private OrganizationServiceProxy _serviceProxy;
  private IOrganizationService _service;

  #endregion Class Level Members

  #region How To Sample Code
  /// <summary>
  /// This method first connects to the Organization service. Afterwards,
  /// basic LINQ queries are performed.
  /// </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;

     CreateRequiredRecords();

     // Create the ServiceContext object that will generate
     // the IQueryable collections for LINQ calls.

     ServiceContext svcContext = new ServiceContext(_service);
     // Loop through all CRM account using the IQueryable interface
     // on the ServiceContext object
     var accounts = from a in svcContext.AccountSet
                    select new Account
                    {
                     Name = a.Name,
                     Address1_County = a.Address1_County
                    };
     System.Console.WriteLine("List all accounts in CRM");
     System.Console.WriteLine("========================");
     foreach (var a in accounts)
     {
      System.Console.WriteLine(a.Name + " " + a.Address1_County);
     }
     System.Console.WriteLine();
     System.Console.WriteLine("<End of Listing>");
     System.Console.WriteLine();
     //OUTPUT:
     //List all accounts in CRM
     //========================
     //Fourth Coffee
     //School of Fine Art Lake County
     //Tailspin Toys King County
     //Woodgrove Bank
     //Contoso, Ltd. Saint Louis County

     //<End of Listing>
     System.Console.WriteLine();



     // Retrieve all accounts owned by the user who has read access rights
     // to the accounts and where the last name of the user is not Cannon.
     var queryAccounts = from a in svcContext.AccountSet
                         join owner in svcContext.SystemUserSet
                           on a.OwnerId.Id equals owner.SystemUserId
                         where owner.LastName != "Cannon"
                         select new Account
                         {
                          Name = a.Name,
                          Address1_City = a.Address1_City
                         };
     System.Console.WriteLine("Accounts not owned by user w/ last name 'Cannon'");
     System.Console.WriteLine("================================================");
     foreach (var a in queryAccounts)
     {
      System.Console.WriteLine(a.Name + " " + a.Address1_County);
     }
     System.Console.WriteLine();
     System.Console.WriteLine("<End of Listing>");
     System.Console.WriteLine();
     //OUTPUT:
     //Accounts not owned by user w/ last name 'Cannon'
     //================================================
     //Fourth Coffee
     //School of Fine Art
     //Tailspin Toys
     //Woodgrove Bank
     //Contoso, Ltd.

     //<End of Listing>
     System.Console.WriteLine();



     // Return a count of all accounts which have a county specified
     // in their address.
     int accountsWithCounty = (from a in svcContext.AccountSet
                               where (a.Address1_County != null)
                               select new Account
                               {
                                Name = a.Name,
                                Address1_City = a.Address1_City
                               }).ToArray().Count();
     System.Console.Write("Number of accounts with a county specified: ");
     System.Console.WriteLine(accountsWithCounty);
     System.Console.WriteLine();
     //OUTPUT:
     //Number of accounts with a county specified: 3
     System.Console.WriteLine();



     // Return a count of states in which we have an account. This
     // uses the 'distinct' keyword which counts a state only one time.
     int statesWithAccounts = (from a in svcContext.AccountSet
                               where (a.Address1_StateOrProvince != null)
                               select a.Address1_StateOrProvince)
                               .Distinct().ToArray().Count();
     System.Console.Write("Number of unique states that contain accounts: ");
     System.Console.WriteLine(statesWithAccounts);
     System.Console.WriteLine();
     //OUTPUT:
     //Number of unique states that contain accounts: 3
     System.Console.WriteLine();



     // Return contacts where the city equals Redmond AND the first
     // name is Joe OR John.
     var queryContacts = from c in svcContext.ContactSet
                         where (c.Address1_City == "Redmond") &amp;&amp;
                               (c.FirstName.Equals("Joe") ||
                                c.FirstName.Equals("John"))
                         select new Contact
                         {
                          FirstName = c.FirstName,
                          LastName = c.LastName,
                          Address1_City = c.Address1_City
                         };
     System.Console.WriteLine("Contacts in Redmond named Joe OR John");
     System.Console.WriteLine("=====================================");
     foreach (var c in queryContacts)
     {
      System.Console.WriteLine(c.FirstName + " " +
          c.LastName + " " + c.Address1_City);
     }
     System.Console.WriteLine();
     System.Console.WriteLine("<End of Listing>");
     System.Console.WriteLine();
     //OUTPUT:
     //Contacts in Redmond named Joe OR John
     //=====================================
     //Joe  Redmond
     //John  Redmond
     //Joe  Redmond

     //<End of Listing>

     System.Console.WriteLine();


     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;
   }
  }

  /// <summary>
  /// Creates any entity records that this sample requires.
  /// </summary>
  public void CreateRequiredRecords()
  {
   // Create 5 Accounts and 5 Contacts for the LINQ samples.
   Account account = new Account
   {
    Name = "Fourth Coffee",
    Address1_StateOrProvince = "Colorado",
   };
   _recordIds.Add(_service.Create(account), Account.EntityLogicalName);
   account = new Account
   {
    Name = "School of Fine Art",
    Address1_StateOrProvince = "Illinois",
    Address1_County = "Lake County"
   };
   _recordIds.Add(_service.Create(account), Account.EntityLogicalName);
   account = new Account
   {
    Name = "Tailspin Toys",
    Address1_StateOrProvince = "Washington",
    Address1_County = "King County",
   };
   _recordIds.Add(_service.Create(account), Account.EntityLogicalName);
   account = new Account
   {
    Name = "Woodgrove Bank",
    Address1_StateOrProvince = "Washington"
   };
   _recordIds.Add(_service.Create(account), Account.EntityLogicalName);
   account = new Account
   {
    Name = "Contoso, Ltd.",
    Address1_County = "Saint Louis County"
   };
   _recordIds.Add(_service.Create(account), Account.EntityLogicalName);

   Contact contact = new Contact
   {
    FirstName = "Joe",
    Address1_City = "Redmond",
   };
   _recordIds.Add(_service.Create(contact), Contact.EntityLogicalName);
   contact = new Contact
   {
    FirstName = "John",
    Address1_City = "Redmond",
   };
   _recordIds.Add(_service.Create(contact), Contact.EntityLogicalName);
   contact = new Contact
   {
    FirstName = "John",
    Address1_City = "Cleveland",
   };
   _recordIds.Add(_service.Create(contact), Contact.EntityLogicalName);
   contact = new Contact
   {
    FirstName = "Joe",
    Address1_City = "Redmond",
   };
   _recordIds.Add(_service.Create(contact), Contact.EntityLogicalName);
   contact = new Contact
   {
    FirstName = "Jim",
    Address1_City = "Redmond",
   };
   _recordIds.Add(_service.Create(contact), Contact.EntityLogicalName);
  }

  /// <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 toBeDeleted = true;

   if (prompt)
   {
    // Ask the user if the created entities should be deleted.
    Console.Write("\nDo you want these entity records deleted? (y/n) [y]: ");
    String answer = Console.ReadLine();
    if (answer.StartsWith("y") ||
        answer.StartsWith("Y") ||
        answer == String.Empty)
    {
     toBeDeleted = true;
    }
    else
    {
     toBeDeleted = false;
    }
   }

   if (toBeDeleted)
   {
    // Delete all records created in this sample.
    foreach (var record in _recordIds)
    {
     _service.Delete(record.Value, record.Key);
    }
    Console.WriteLine("Entity record(s) have been deleted.");
   }
  }

  #endregion How To Sample Code

  #region Main method

  /// <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();

    CreateALinqQuery app = new CreateALinqQuery();
    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 method
 }
}

See Also

OrganizationServiceContext
Build queries with LINQ (.NET language-integrated query)
Sample: Complex LINQ queries

Microsoft Dynamics 365

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