Exemples de requête LINQ

 

Date de publication : janvier 2017

S’applique à : Dynamics 365 (online), Dynamics 365 (on-premises), Dynamics CRM 2016, Dynamics CRM Online

Cette rubrique contient plusieurs exemples de requêtes LINQ. Pour obtenir l’exemple complet, consultez Exemple : Requêtes LINQ complexes.

Contenu de la rubrique

Clause Where simple

Jointure et clause Where simple

Utiliser l’opérateur Distinct

Jointure interne simple

Jointure réflexive

Jointures doubles et multiples

Joindre à l’aide de champs d’entités

Jointure gauche à liaison tardive

Utiliser l’opérateur Equals

Utiliser l’opérateur Not Equals

Utiliser une requête LINQ basée sur une méthode avec une clause Where

Utiliser l’opérateur Greater Than

Utiliser les opérateurs Greater Than or Equals et Less Than or Equals

Utiliser l’opérateur Contains

Utiliser l’opérateur Does Not Contain

Utiliser les opérateurs StartsWith et EndsWith

Utiliser les opérateurs And et Or

Utiliser l’opérateur OrderBy

Utiliser les opérateurs First et Single

Récupération des valeurs mises en forme

Utiliser les opérateurs Skip et Take sans pagination

Utiliser les opérateurs FirstOrDefault et SingleOrDefault

Utiliser une jointure réflexive avec une condition sur l’entité liée

Utiliser une transformation dans la clause Where

Utiliser un tri de pagination

Récupérer des colonnes d’entité associées pour les relations de type 1 à N

Utiliser .Value pour récupérer la valeur d’un attribut

Projections multiples, cast d’un nouveau type de données vers différents types

Utiliser la méthode GetAttributeValue

Utiliser les méthodes Math

Utiliser plusieurs clauses Select et Where

Utiliser SelectMany

Utiliser les opérations de chaîne

Utiliser deux clauses Where

Utiliser LoadProperty pour récupérer des enregistrements associés

Clause Where simple

L’exemple suivant montre comment récupérer une liste de comptes où Name contient « Contoso ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_where1 = from a in svcContext.AccountSet
                    where a.Name.Contains("Contoso")
                    select a;
 foreach (var a in query_where1)
 {
  System.Console.WriteLine(a.Name + " " + a.Address1_City);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_where1 = From c In svcContext.AccountSet _
                    Where c.Name.Contains("Contoso") _
                    Select c

 For Each c In query_where1
  Console.WriteLine(c.Name & " " & c.Address1_City)
 Next c
End Using

L’exemple suivant montre comment récupérer une liste de comptes où Name contient « Contoso » et Address1_City a la valeur « Redmond ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_where2 = from a in svcContext.AccountSet
                    where a.Name.Contains("Contoso")
                    where a.Address1_City == "Redmond"
                    select a;

 foreach (var a in query_where2)
 {
  System.Console.WriteLine(a.Name + " " + a.Address1_City);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_where2 = From c In svcContext.AccountSet _
                    Where c.Name.Contains("Contoso") _
                    Where c.Address1_City.Equals("Redmond") _
                    Select c

 For Each c In query_where2
  Console.WriteLine(c.Name & " " & c.Address1_City)
 Next c
End Using

Jointure et clause Where simple

L’exemple suivant montre comment récupérer le compte Name et le contact LastName où le compte Name contient « Contoso » et le contact LastName contient « Smith » et est le contact principal du compte.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_where3 = from c in svcContext.ContactSet
                    join a in svcContext.AccountSet
                    on c.ContactId equals a.PrimaryContactId.Id
                    where a.Name.Contains("Contoso")
                    where c.LastName.Contains("Smith")
                    select new
                    {
                     account_name = a.Name,
                     contact_name = c.LastName
                    };

 foreach (var c in query_where3)
 {
  System.Console.WriteLine("acct: " +
   c.account_name +
   "\t\t\t" +
   "contact: " +
   c.contact_name);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_where3 = From c In svcContext.ContactSet _
                    Join a In svcContext.AccountSet _
                    On c.ContactId Equals a.account_primary_contact.Id _
                    Where a.Name.Contains("Contoso") _
                    Where c.LastName.Contains("Smith") _
                    Select New With {Key .account_name = a.Name,
                                     Key .contact_name = c.LastName}

 For Each c In query_where3
  Console.WriteLine("acct: " & c.account_name & vbTab & vbTab _
                    & vbTab & "contact: " & c.contact_name)
 Next c
End Using

Utiliser l’opérateur Distinct

L’exemple suivant montre comment récupérer une liste distincte de noms de contact. Bien qu’il puisse exister des doublons, chaque nom n’est répertorié qu’une seule fois.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_distinct = (from c in svcContext.ContactSet
                       select c.LastName).Distinct();
 foreach (var c in query_distinct)
 {
  System.Console.WriteLine(c);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_distinct = ( _
     From c In svcContext.ContactSet _
     Select c.LastName).Distinct()
 For Each c In query_distinct
  Console.WriteLine(c)
 Next c
End Using

Jointure interne simple

L’exemple suivant montre comment récupérer les informations concernant un compte et le contact répertorié comme contact principal du compte.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_join1 = from c in svcContext.ContactSet
                   join a in svcContext.AccountSet
                  on c.ContactId equals a.PrimaryContactId.Id
                   select new
                   {
                    c.FullName,
                    c.Address1_City,
                    a.Name,
                    a.Address1_Name
                   };
 foreach (var c in query_join1)
 {
  System.Console.WriteLine("acct: " +
   c.Name +
   "\t\t\t" +
   "contact: " +
   c.FullName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_join1 = From c In svcContext.ContactSet _
                   Join a In svcContext.AccountSet _
                   On c.ContactId Equals a.account_primary_contact.Id _
                   Select New With {Key c.FullName, Key c.Address1_City,
                                    Key a.Name, Key a.Address1_Name}
 For Each c In query_join1
  Console.WriteLine("acct: " & c.Name & vbTab & vbTab _
                    & vbTab & "contact: " & c.FullName)
 Next c
End Using

Jointure réflexive

L’exemple suivant montre comment récupérer les informations concernant les comptes où un compte est le compte parent d’un autre compte.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_join5 = from a in svcContext.AccountSet
                   join a2 in svcContext.AccountSet
                   on a.ParentAccountId.Id equals a2.AccountId

                   select new
                   {
                    account_name = a.Name,
                    account_city = a.Address1_City
                   };
 foreach (var c in query_join5)
 {
  System.Console.WriteLine(c.account_name + "  " + c.account_city);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_join5 = From a In svcContext.AccountSet _
                   Join a2 In svcContext.AccountSet _
                   On a.ParentAccountId.Id Equals a2.AccountId _
                   Select New With {
                         Key .account_name = a.Name,
                         Key .account_city = a.Address1_City
                         }
 For Each c In query_join5
  Console.WriteLine(c.account_name & "  " & c.account_city)
 Next c
End Using

Jointures doubles et multiples

L’exemple suivant montre comment récupérer les informations du compte, contact et prospect où le contact est le contact principal du compte et le prospect était le prospect d’origine du compte.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_join4 = from a in svcContext.AccountSet
                   join c in svcContext.ContactSet
                   on a.PrimaryContactId.Id equals c.ContactId
                   join l in svcContext.LeadSet
                   on a.OriginatingLeadId.Id equals l.LeadId
                   select new
                   {
                    contact_name = c.FullName,
                    account_name = a.Name,
                    lead_name = l.FullName
                   };
 foreach (var c in query_join4)
 {
  System.Console.WriteLine(c.contact_name +
   "  " +
   c.account_name +
   "  " +
   c.lead_name);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_join4 = From a In svcContext.AccountSet _
                   Join c In svcContext.ContactSet _
                   On a.PrimaryContactId.Id Equals c.ContactId _
                   Join l In svcContext.LeadSet _
                   On a.OriginatingLeadId.Id Equals l.LeadId _
                   Select New With {Key .contact_name = c.FullName,
                                    Key .account_name = a.Name,
                                    Key .lead_name = l.FullName}
 For Each c In query_join4
  Console.WriteLine(c.contact_name & "  " & c.account_name _
                    & "  " & c.lead_name)
 Next c
End Using

L’exemple suivant montre comment récupérer les informations de compte et de contact où un compte est le compte parent d’un autre compte et le contact était le contact principal du compte.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_join6 = from c in svcContext.ContactSet
                   join a in svcContext.AccountSet
                   on c.ContactId equals a.PrimaryContactId.Id
                   join a2 in svcContext.AccountSet
                   on a.ParentAccountId.Id equals a2.AccountId
                   select new
                   {
                    contact_name = c.FullName,
                    account_name = a.Name
                   };
 foreach (var c in query_join6)
 {
  System.Console.WriteLine(c.contact_name + "  " + c.account_name);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_join6 = From c In svcContext.ContactSet _
                   Join a In svcContext.AccountSet _
                   On c.ContactId Equals a.PrimaryContactId.Id _
                   Join a2 In svcContext.AccountSet _
                   On a.ParentAccountId.Id Equals a2.AccountId _
                   Select New With {Key .contact_name = c.FullName,
                                    Key .account_name = a.Name}
 For Each c In query_join6
  Console.WriteLine(c.contact_name & "  " & c.account_name)
 Next c
End Using

Joindre à l’aide de champs d’entités

L’échantillon suivant montre comment récupérer des informations concernant les comptes à partir d’une liste

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var list_join = (from a in svcContext.AccountSet
                  join c in svcContext.ContactSet
                  on a.PrimaryContactId.Id equals c.ContactId
                  where a.Name == "Contoso Ltd" &&
                  a.Address1_Name == "Contoso Pharmaceuticals"
                  select a).ToList();
 foreach (var c in list_join)
 {
  System.Console.WriteLine("Account " + list_join[0].Name
      + " and it's primary contact "
      + list_join[0].PrimaryContactId.Id);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim list_join = ( _
     From a In svcContext.AccountSet _
     Join c In svcContext.ContactSet _
     On a.PrimaryContactId.Id Equals c.ContactId _
     Where a.Name.Equals("Contoso Ltd") _
     And a.Address1_Name.Equals("Contoso Pharmaceuticals") _
     Select a).ToList()
 For Each c In list_join
  Console.WriteLine("Account " & list_join(0).Name _
                    & " and it's primary contact " _
                    & list_join(0).PrimaryContactId.Id.ToString())
 Next c
End Using

Jointure gauche à liaison tardive

L’exemple suivant illustre une jointure gauche. Une jointure gauche est conçue pour retourner les parents avec et sans les enfants à partir de deux sources. Il existe une corrélation entre le parent et l’enfant, mais aucun enfant ne peut exister réellement.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_join8 = from a in svcContext.AccountSet
                   join c in svcContext.ContactSet
                   on a.PrimaryContactId.Id equals c.ContactId
                   into gr
                   from c_joined in gr.DefaultIfEmpty()
                   select new
                   {
                    contact_name = c_joined.FullName,
                    account_name = a.Name
                   };
 foreach (var c in query_join8)
 {
  System.Console.WriteLine(c.contact_name + "  " + c.account_name);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_join8 = From a In svcContext.AccountSet _
                   Group Join c In svcContext.ContactSet _
                   On a.PrimaryContactId.Id Equals c.ContactId Into gr = _
                   Group From c_joined In gr.DefaultIfEmpty() _
                   Select New With {Key .contact_name = c_joined.FullName,
                                    Key .account_name = a.Name}
 For Each c In query_join8
  Console.WriteLine(c.contact_name & "  " & c.account_name)
 Next c
End Using

Utiliser l’opérateur Equals

L’exemple suivant montre comment récupérer une liste de contacts où FirstName a la valeur « Colin ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_equals1 = from c in svcContext.ContactSet
                     where c.FirstName.Equals("Colin")
                     select new
                     {
                      c.FirstName,
                      c.LastName,
                      c.Address1_City
                     };
 foreach (var c in query_equals1)
 {
  System.Console.WriteLine(c.FirstName +
   " " + c.LastName +
   " " + c.Address1_City);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_equals1 = From c In svcContext.ContactSet _
                     Where c.FirstName.Equals("Colin") _
                     Select New With {Key c.FirstName,
                                      Key c.LastName,
                                      Key c.Address1_City}
 For Each c In query_equals1
  Console.WriteLine(c.FirstName & " " & c.LastName & " " _
                    & c.Address1_City)
 Next c
End Using

L’échantillon suivant montre comment récupérer une liste de contacts où FamilyStatusCode a la valeur 3. Cela correspond à l'option État civil de Divorcé(e).

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_equals2 = from c in svcContext.ContactSet
                     where c.FamilyStatusCode.Equals(3)
                     select new
                     {
                      c.FirstName,
                      c.LastName,
                      c.Address1_City
                     };
 foreach (var c in query_equals2)
 {
  System.Console.WriteLine(c.FirstName +
   " " + c.LastName +
   " " + c.Address1_City);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_equals2 = From c In svcContext.ContactSet _
                     Where c.FamilyStatusCode.Equals(3) _
                     Select New With {Key c.FirstName,
                                      Key c.LastName,
                                      Key c.Address1_City}
 For Each c In query_equals2
  Console.WriteLine(c.FirstName & " " & c.LastName & " " _
                    & c.Address1_City)
 Next c
End Using

Utiliser l’opérateur Not Equals

L’exemple suivant montre comment récupérer une liste de contacts où Address1_City n’a pas la valeur « Redmond ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_ne1 = from c in svcContext.ContactSet
                 where c.Address1_City != "Redmond"
                 select new
                 {
                  c.FirstName,
                  c.LastName,
                  c.Address1_City
                 };
 foreach (var c in query_ne1)
 {
  System.Console.WriteLine(c.FirstName + " " +
   c.LastName + " " + c.Address1_City);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_ne1 = From c In svcContext.ContactSet _
                 Where c.Address1_City IsNot "Redmond" _
                 Select New With {Key c.FirstName,
                                  Key c.LastName,
                                  Key c.Address1_City}
 For Each c In query_ne1
  Console.WriteLine(c.FirstName & " " & c.LastName _
                    & " " & c.Address1_City)
 Next c
End Using

L’exemple suivant montre comment récupérer une liste de contacts où FirstName n’a pas la valeur « Colin ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_ne2 = from c in svcContext.ContactSet
                 where !c.FirstName.Equals("Colin")
                 select new
                 {
                  c.FirstName,
                  c.LastName,
                  c.Address1_City
                 };

 foreach (var c in query_ne2)
 {
  System.Console.WriteLine(c.FirstName + " " +
   c.LastName + " " + c.Address1_City);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_ne2 = From c In svcContext.ContactSet _
                 Where (Not c.FirstName.Equals("Colin")) _
                 Select New With {Key c.FirstName,
                                  Key c.LastName,
                                  Key c.Address1_City}

 For Each c In query_ne2
  Console.WriteLine(c.FirstName & " " & c.LastName & " " _
                    & c.Address1_City)
 Next c
End Using

Utiliser une requête LINQ basée sur une méthode avec une clause Where

L’exemple suivant montre comment récupérer une liste de contacts où LastName a la valeur « Smith » ou contient « Smi ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var methodResults = svcContext.ContactSet
  .Where(a => a.LastName == "Smith");
 var methodResults2 = svcContext.ContactSet
  .Where(a => a.LastName.StartsWith("Smi"));
 Console.WriteLine();
 Console.WriteLine("Method query using Lambda expression");
 Console.WriteLine("---------------------------------------");
 foreach (var a in methodResults)
 {
  Console.WriteLine("Name: " + a.FirstName + " " + a.LastName);
 }
 Console.WriteLine("---------------------------------------");
 Console.WriteLine("Method query 2 using Lambda expression");
 Console.WriteLine("---------------------------------------");
 foreach (var a in methodResults2)
 {
  Console.WriteLine("Name: " + a.Attributes["firstname"] +
   " " + a.Attributes["lastname"]);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim methodResults = svcContext.ContactSet _
                     .Where(Function(a) a.LastName.Equals("Smith"))
 Dim methodResults2 = svcContext.ContactSet _
                      .Where(Function(a) a.LastName.StartsWith("Smi"))
 Console.WriteLine()
 Console.WriteLine("Method query using Lambda expression")
 Console.WriteLine("---------------------------------------")
 For Each a In methodResults
  Console.WriteLine("Name: " & a.FirstName & " " & a.LastName)
 Next a
 Console.WriteLine("---------------------------------------")
 Console.WriteLine("Method query 2 using Lambda expression")
 Console.WriteLine("---------------------------------------")
 For Each a In methodResults2
  Console.WriteLine("Name: " & a.Attributes("firstname").ToString() _
                    & " " & a.Attributes("lastname").ToString())
 Next a
End Using

Utiliser l’opérateur Greater Than

L’exemple suivant montre comment récupérer une liste de contacts avec une date Anniversary postérieure au 5 février 2010.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_gt1 = from c in svcContext.ContactSet
                 where c.Anniversary > new DateTime(2010, 2, 5)
                 select new
                 {
                  c.FirstName,
                  c.LastName,
                  c.Address1_City
                 };

 foreach (var c in query_gt1)
 {
  System.Console.WriteLine(c.FirstName + " " +
   c.LastName + " " + c.Address1_City);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_gt1 = From c In svcContext.ContactSet _
                 Where c.Anniversary > New Date(2010, 2, 5) _
                 Select New With {Key c.FirstName,
                                  Key c.LastName,
                                  Key c.Address1_City}

 For Each c In query_gt1
  Console.WriteLine(c.FirstName & " " & c.LastName _
                    & " " & c.Address1_City)
 Next c
End Using

L’exemple suivant montre comment récupérer des contacts avec une valeur CreditLimit supérieure à 20 000 USD.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_gt2 = from c in svcContext.ContactSet
                 where c.CreditLimit.Value > 20000
                 select new
                 {
                  c.FirstName,
                  c.LastName,
                  c.Address1_City
                 };
 foreach (var c in query_gt2)
 {
  System.Console.WriteLine(c.FirstName + " " +
   c.LastName + " " + c.Address1_City);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_gt2 = From c In svcContext.ContactSet _
                 Where c.CreditLimit.Value > 20000 _
                 Select New With {Key c.FirstName,
                                  Key c.LastName,
                                  Key c.Address1_City}
 For Each c In query_gt2
  Console.WriteLine(c.FirstName & " " & c.LastName _
                    & " " & c.Address1_City)
 Next c
End Using

Utiliser les opérateurs Greater Than or Equals et Less Than or Equals

L’exemple suivant montre comment récupérer des contacts avec une valeur CreditLimit supérieure à 200 USD et inférieure à 400 USD.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_gele1 = from c in svcContext.ContactSet
                   where c.CreditLimit.Value >= 200 &&
                   c.CreditLimit.Value <= 400
                   select new
                   {
                    c.FirstName,
                    c.LastName
                   };
 foreach (var c in query_gele1)
 {
  System.Console.WriteLine(c.FirstName + " " + c.LastName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_gele1 = From c In svcContext.ContactSet _
                   Where c.CreditLimit.Value >= 200 _
                   AndAlso c.CreditLimit.Value <= 400 _
                   Select New With {Key c.FirstName,
                                    Key c.LastName}
 For Each c In query_gele1
  Console.WriteLine(c.FirstName &amp; " " &amp; c.LastName)
 Next c
End Using

Utiliser l’opérateur Contains

L’exemple suivant montre comment récupérer des contacts où Description contient « Alpine ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_contains1 = from c in svcContext.ContactSet
                       where c.Description.Contains("Alpine")
                       select new
                       {
                        c.FirstName,
                        c.LastName
                       };
 foreach (var c in query_contains1)
 {
  System.Console.WriteLine(c.FirstName + " " + c.LastName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_contains1 = From c In svcContext.ContactSet _
                       Where c.Description.Contains("Alpine") _
                       Select New With {Key c.FirstName,
                                        Key c.LastName}
 For Each c In query_contains1
  Console.WriteLine(c.FirstName & " " & c.LastName)
 Next c
End Using

Utiliser l’opérateur Does Not Contain

L’exemple suivant montre comment récupérer des contacts où Description ne contient pas « Coho ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_contains2 = from c in svcContext.ContactSet
                       where !c.Description.Contains("Coho")
                       select new
                       {
                        c.FirstName,
                        c.LastName
                       };
 foreach (var c in query_contains2)
 {
  System.Console.WriteLine(c.FirstName + " " + c.LastName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_contains2 = From c In svcContext.ContactSet _
                       Where (Not c.Description.Contains("Coho")) _
                       Select New With {Key c.FirstName,
                                        Key c.LastName}
 For Each c In query_contains2
  Console.WriteLine(c.FirstName.ToString() & " " _
                    & c.LastName.ToString())
 Next c
End Using

Utiliser les opérateurs StartsWith et EndsWith

L’exemple suivant montre comment récupérer des contacts où FirstName commence par « Bri ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_startswith1 = from c in svcContext.ContactSet
                         where c.FirstName.StartsWith("Bri")
                         select new
                         {
                          c.FirstName,
                          c.LastName
                         };
 foreach (var c in query_startswith1)
 {
  System.Console.WriteLine(c.FirstName + " " + c.LastName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_startswith1 = From c In svcContext.ContactSet _
                         Where c.FirstName.StartsWith("Bri") _
                         Select New With {Key c.FirstName,
                                          Key c.LastName}
 For Each c In query_startswith1
  Console.WriteLine(c.FirstName.ToString() & " " _
                    & c.LastName.ToString())
 Next c
End Using

L’exemple suivant montre comment récupérer des contacts où LastName se termine par « cox ».

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_endswith1 = from c in svcContext.ContactSet
                       where c.LastName.EndsWith("cox")
                       select new
                       {
                        c.FirstName,
                        c.LastName
                       };
 foreach (var c in query_endswith1)
 {
  System.Console.WriteLine(c.FirstName + " " + c.LastName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_endswith1 = From c In svcContext.ContactSet _
                       Where c.LastName.EndsWith("cox") _
                       Select New With {Key c.FirstName,
                                        Key c.LastName}
 For Each c In query_endswith1
  Console.WriteLine(c.FirstName.ToString() & " " _
                    & c.LastName.ToString())
 Next c
End Using

Utiliser les opérateurs And et Or

L’exemple suivant montre comment récupérer des contacts où Address1_City a la valeur « Redmond » ou « Bellevue » et CreditLimit a une valeur supérieure à 200 USD.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_andor1 = from c in svcContext.ContactSet
                    where ((c.Address1_City == "Redmond" ||
                    c.Address1_City == "Bellevue") &&
                    (c.CreditLimit.Value != null &&
                    c.CreditLimit.Value >= 200))
                    select c;

 foreach (var c in query_andor1)
 {
  System.Console.WriteLine(c.LastName + ", " + c.FirstName + " " +
   c.Address1_City + " " + c.CreditLimit.Value);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_andor1 = From c In svcContext.ContactSet _
                    Where c.Address1_City.Equals("Redmond") _
                    OrElse c.Address1_City.Equals("Bellevue") _
                    AndAlso c.CreditLimit.Value >= 200 _
                    Select New With {Key c.FirstName,
                                     Key c.LastName,
                                     Key c.CreditLimit,
                                     Key c.Address1_City}
 For Each c In query_andor1
  Console.WriteLine(c.LastName.ToString() & ", " _
                    & c.FirstName.ToString() & " " _
                    & c.Address1_City.ToString() & " " _
                    & c.CreditLimit.Value.ToString())
 Next c
End Using

Utiliser l’opérateur OrderBy

L’exemple suivant montre comment récupérer des contacts classés par CreditLimit dans l’ordre décroissant.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_orderby1 = from c in svcContext.ContactSet
                      where !c.CreditLimit.Equals(null)
                      orderby c.CreditLimit descending
                      select new
                      {
                       limit = c.CreditLimit,
                       first = c.FirstName,
                       last = c.LastName
                      };
 foreach (var c in query_orderby1)
 {
  System.Console.WriteLine(c.limit.Value + " " +
   c.last + ", " + c.first);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_orderby1 = From c In svcContext.ContactSet _
                      Where (Not c.CreditLimit.Equals(Nothing)) _
                      Order By c.CreditLimit Descending _
                      Select New With {Key .limit = c.CreditLimit,
                                       Key .first = c.FirstName,
                                       Key .last = c.LastName}
 For Each c In query_orderby1
  Console.WriteLine(c.limit.Value & " " & c.last & ", " _
                    & c.first)
 Next c
End Using

L’exemple suivant montre comment récupérer des contacts classés par LastName dans l’ordre décroissant et par FirstName dans l’ordre croissant.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_orderby2 = from c in svcContext.ContactSet
                      orderby c.LastName descending,
                      c.FirstName ascending
                      select new
                      {
                       first = c.FirstName,
                       last = c.LastName
                      };

 foreach (var c in query_orderby2)
 {
  System.Console.WriteLine(c.last + ", " + c.first);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_orderby2 = From c In svcContext.ContactSet _
                      Order By c.LastName Descending, _
                      c.FirstName Ascending _
                      Select New With {Key .first = c.FirstName,
                                       Key .last = c.LastName}

 For Each c In query_orderby2
  Console.WriteLine(c.last & ", " & c.first)
 Next c
End Using

Utiliser les opérateurs First et Single

L’exemple suivant montre comment récupérer uniquement le premier enregistrement de contact retourné et récupérer un seul enregistrement de contact qui répond aux critères.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 Contact firstcontact = svcContext.ContactSet.First();

 Contact singlecontact = svcContext.ContactSet.Single(c => c.ContactId == _contactId1);
 System.Console.WriteLine(firstcontact.LastName + ", " +
  firstcontact.FirstName + " is the first contact");
 System.Console.WriteLine("==========================");
 System.Console.WriteLine(singlecontact.LastName + ", " +
  singlecontact.FirstName + " is the single contact");
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim firstcontact As Contact = svcContext.ContactSet _
                               .First()
 Console.WriteLine(firstcontact.LastName & ", " _
                   & firstcontact.FirstName _
                   & " is the first contact")
 Console.WriteLine("==========================")
 Dim singlecontact As Contact =
     svcContext.ContactSet _
     .Single(Function(c) c.ContactId.Value.Equals(_contactId1))
 Console.WriteLine(singlecontact.LastName & ", " _
                   & singlecontact.FirstName _
                   & " is the single contact")
End Using

Récupération des valeurs mises en forme

L’exemple suivant montre comment récupérer l’étiquette d’une option optionset, dans ce cas, la valeur du statut d’enregistrement actuel.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var list_retrieve1 = from c in svcContext.ContactSet
                      where c.ContactId == _contactId1
                      select new { StatusReason = c.FormattedValues["statuscode"] };
 foreach (var c in list_retrieve1)
 {
  System.Console.WriteLine("Status: " + c.StatusReason);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim list_retrieve1 = From c In svcContext.ContactSet _
                      Where c.ContactId.Value.Equals(_contactId1) _
                      Select New With
                             {Key .StatusReason =
                                 c.FormattedValues("statuscode")}
 For Each c In list_retrieve1
  Console.WriteLine("Status: " & c.StatusReason)
 Next c
End Using

Utiliser les opérateurs Skip et Take sans pagination

L’exemple suivant montre comment récupérer uniquement deux enregistrements après avoir ignoré deux enregistrements où LastName n’a pas la valeur « Parker » à l’aide des opérateurs Skip et Take.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{

 var query_skip = (from c in svcContext.ContactSet
                   where c.LastName != "Parker"
                   orderby c.FirstName
                   select new
                       {
                        last = c.LastName,
                        first = c.FirstName
                       }).Skip(2).Take(2);
 foreach (var c in query_skip)
 {
  System.Console.WriteLine(c.first + " " + c.last);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_skip = ( _
     From c In svcContext.ContactSet _
     Where c.LastName IsNot "Parker" _
     Order By c.FirstName _
     Select New With {Key .last = c.LastName,
                      Key .first = c.FirstName}).Skip(2).Take(2)
 For Each c In query_skip
  Console.WriteLine(c.first & " " & c.last)
 Next c
End Using

Utiliser les opérateurs FirstOrDefault et SingleOrDefault

L’opérateur FirstOrDefault retourne le premier élément d’une séquence ou une valeur par défaut si aucun élément n’est trouvé. L’opérateur SingleOrDefault retourne un seul élément spécifique d’une séquence ou une valeur par défaut si cet élément n’est pas trouvé. L’exemple suivant montre comment utiliser ces opérateurs.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{

 Contact firstorcontact = svcContext.ContactSet.FirstOrDefault();

 Contact singleorcontact = svcContext.ContactSet
  .SingleOrDefault(c => c.ContactId == _contactId1);


 System.Console.WriteLine(firstorcontact.FullName +
  " is the first contact");
 System.Console.WriteLine("==========================");
 System.Console.WriteLine(singleorcontact.FullName +
  " is the single contact");
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim firstorcontact As Contact =
     svcContext.ContactSet.FirstOrDefault()
 Console.WriteLine(firstorcontact.FullName & " is the first contact")

 Console.WriteLine("==========================")
 Dim singleorcontact As Contact =
     svcContext.ContactSet _
     .SingleOrDefault(Function(c) c.ContactId.Value.Equals(_contactId1))
 Console.WriteLine(singleorcontact.FullName & " is the single contact")
End Using

Utiliser une jointure réflexive avec une condition sur l’entité liée

L’exemple suivant montre comment récupérer les noms de deux comptes où un compte est le compte parent de l’autre.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_joincond = from a1 in svcContext.AccountSet
                      join a2 in svcContext.AccountSet
                      on a1.ParentAccountId.Id equals a2.AccountId
                      where a2.AccountId == _accountId1
                      select new { Account = a1, Parent = a2 };
 foreach (var a in query_joincond)
 {
  System.Console.WriteLine(a.Account.Name + " " + a.Parent.Name);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_joincond = From a1 In svcContext.AccountSet _
                      Join a2 In svcContext.AccountSet _
                      On a1.ParentAccountId.Id Equals a2.AccountId _
                      Where a2.AccountId.Value.Equals(_accountId1) _
                      Select New With {Key .Account = a1,
                                       Key .Parent = a2}
 For Each a In query_joincond
  Console.WriteLine(a.Account.Name & " " & a.Parent.Name)
 Next a
End Using

Utiliser une transformation dans la clause Where

L’exemple suivant montre comment récupérer un contact spécifique dont la date d’anniversaire est postérieure au 1er janvier 2010.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_wheretrans = from c in svcContext.ContactSet
                        where c.ContactId == _contactId1 &&
                        c.Anniversary > DateTime.Parse("1/1/2010")
                        select new
                        {
                         c.FirstName,
                         c.LastName
                        };
 foreach (var c in query_wheretrans)
 {
  System.Console.WriteLine(c.FirstName + " " + c.LastName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_wheretrans = From c In svcContext.ContactSet _
                        Where c.ContactId.Value.Equals(_contactId1) _
                        AndAlso c.Anniversary > Date.Parse("1/1/2010") _
                        Select New With {Key c.FirstName,
                                         Key c.LastName}
 For Each c In query_wheretrans
  Console.WriteLine(c.FirstName & " " & c.LastName)
 Next c
End Using

Utiliser un tri de pagination

L’exemple suivant illustre un tri sur plusieurs colonnes avec une condition supplémentaire.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_pagingsort1 = (from c in svcContext.ContactSet
                          where c.LastName != "Parker"
                          orderby c.LastName ascending,
                          c.FirstName descending
                          select new { c.FirstName, c.LastName })
                          .Skip(2).Take(2);
 foreach (var c in query_pagingsort1)
 {
  System.Console.WriteLine(c.FirstName + " " + c.LastName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_pagingsort1 = ( _
     From c In svcContext.ContactSet _
     Where c.LastName IsNot "Parker" _
     Order By c.LastName Ascending, c.FirstName Descending _
     Select New With {Key c.FirstName,
                      Key c.LastName}).Skip(2).Take(2)
 For Each c In query_pagingsort1
  Console.WriteLine(c.FirstName & " " & c.LastName)
 Next c
End Using

L’exemple suivant illustre un tri de pagination où la colonne triée est différente de la colonne récupérée.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_pagingsort2 = (from c in svcContext.ContactSet
                          where c.LastName != "Parker"
                          orderby c.FirstName descending
                          select new { c.FirstName }).Skip(2).Take(2);
 foreach (var c in query_pagingsort2)
 {
  System.Console.WriteLine(c.FirstName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_pagingsort2 = ( _
     From c In svcContext.ContactSet _
     Where c.LastName IsNot "Parker" _
     Order By c.FirstName Descending _
     Select New With {Key c.FirstName}).Skip(2).Take(2)
 For Each c In query_pagingsort2
  Console.WriteLine(c.FirstName)
 Next c
End Using

L’exemple suivant montre comment récupérer les 10 premiers enregistrements.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_pagingsort3 = (from c in svcContext.ContactSet
                          where c.LastName.StartsWith("W")
                          orderby c.MiddleName ascending,
                          c.FirstName descending
                          select new
                          {
                           c.FirstName,
                           c.MiddleName,
                           c.LastName
                          }).Take(10);
 foreach (var c in query_pagingsort3)
 {
  System.Console.WriteLine(c.FirstName + " " +
   c.MiddleName + " " + c.LastName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_pagingsort3 = ( _
     From c In svcContext.ContactSet _
     Where c.LastName.StartsWith("W") _
     Order By c.MiddleName Ascending, c.FirstName Descending _
     Select New With {Key c.FirstName,
                      Key c.MiddleName,
                      Key c.LastName}).Take(10)
 For Each c In query_pagingsort3
  Console.WriteLine(c.FirstName & " " & c.MiddleName & " " & c.LastName)
 Next c
End Using

Récupérer des colonnes d’entité associées pour les relations de type 1 à N

L’exemple suivant montre comment récupérer des colonnes d’enregistrements de compte et de contact associés.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_retrieve1 = from c in svcContext.ContactSet
                       join a in svcContext.AccountSet
                       on c.ContactId equals a.PrimaryContactId.Id
                       where c.ContactId != _contactId1
                       select new { Contact = c, Account = a };
 foreach (var c in query_retrieve1)
 {
  System.Console.WriteLine("Acct: " + c.Account.Name +
   "\t\t" + "Contact: " + c.Contact.FullName);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_retrieve1 = From c In svcContext.ContactSet _
                       Join a In svcContext.AccountSet _
                       On c.ContactId Equals a.PrimaryContactId.Id _
                       Where Not c.ContactId.Value.Equals(_contactId1) _
                       Select New With {Key .Contact = c,
                                        Key .Account = a}
 For Each c In query_retrieve1
  Console.WriteLine("Acct: " & c.Account.Name & vbTab & vbTab _
                    & "Contact: " & c.Contact.FullName)
 Next c
End Using

Utiliser .Value pour récupérer la valeur d’un attribut

L’exemple suivant illustre l’utilisation de Value pour accéder à la valeur d’un attribut.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{

 var query_value = from c in svcContext.ContactSet
                   where c.ContactId != _contactId2
                   select new
                   {
                    ContactId = c.ContactId != null ?
                     c.ContactId.Value : Guid.Empty,
                    NumberOfChildren = c.NumberOfChildren != null ?
                     c.NumberOfChildren.Value : default(int),
                    CreditOnHold = c.CreditOnHold != null ?
                     c.CreditOnHold.Value : default(bool),
                    Anniversary = c.Anniversary != null ?
                     c.Anniversary.Value : default(DateTime)
                   };

 foreach (var c in query_value)
 {
  System.Console.WriteLine(c.ContactId + " " + c.NumberOfChildren + 
   " " + c.CreditOnHold + " " + c.Anniversary);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_value = From c In svcContext.ContactSet _
                   Where Not c.ContactId.Value.Equals(_contactId2) _
                   Select New With
                          {Key .ContactId = If(
                                  c.ContactId IsNot Nothing,
                                  c.ContactId.Value,
                                  Guid.Empty),
                           Key .NumberOfChildren = If(
                               c.NumberOfChildren IsNot Nothing,
                               c.NumberOfChildren.Value, Nothing),
                           Key .CreditOnHold = If(
                               c.CreditOnHold IsNot Nothing,
                               c.CreditOnHold.Value,
                               Nothing),
                           Key .Anniversary = If(
                               c.Anniversary IsNot Nothing,
                               c.Anniversary.Value,
                               Nothing)}

 For Each c In query_value
  Console.WriteLine(c.ContactId.ToString() & " " _
                    & c.NumberOfChildren & " " _
                    & c.CreditOnHold & " " & c.Anniversary)
 Next c
End Using

Projections multiples, cast d’un nouveau type de données vers différents types

L’exemple suivant illustre les projections multiples et montre comment effectuer un cast des valeurs vers un autre type.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_projections = from c in svcContext.ContactSet
                         where c.ContactId == _contactId1
                         && c.NumberOfChildren != null && 
                         c.Anniversary.Value != null
                         select new
                         {
                          Contact = new Contact { 
                           LastName = c.LastName, 
                           NumberOfChildren = c.NumberOfChildren 
                          },
                          NumberOfChildren = (double)c.NumberOfChildren,
                          Anniversary = c.Anniversary.Value.AddYears(1),
                         };
 foreach (var c in query_projections)
 {
  System.Console.WriteLine(c.Contact.LastName + " " + 
   c.NumberOfChildren + " " + c.Anniversary);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_projections = From c In svcContext.ContactSet _
                         Where c.ContactId.Value.Equals(_contactId1) _
                         And Not c.NumberOfChildren.Equals(Nothing) _
                         And Not c.Anniversary.Equals(Nothing) _
        Select New With
               {Key .Contact =
                   New Contact With
                   {.LastName = c.LastName,
                    .NumberOfChildren = c.NumberOfChildren},
                Key .NumberOfChildren = CDbl(c.NumberOfChildren),
                Key .Anniversary = c.Anniversary.Value.AddYears(1)}
 For Each c In query_projections
  Console.WriteLine(c.Contact.LastName & " " & c.NumberOfChildren _
                    & " " & c.Anniversary)
 Next c
End Using

Utiliser la méthode GetAttributeValue

L’exemple suivant montre comment utiliser la méthode GetAttributeValue<T>.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_getattrib = from c in svcContext.ContactSet
                       where c.GetAttributeValue<Guid>("contactid") != _contactId1
                       select new
                       {
                        ContactId = c.GetAttributeValue<Guid?>("contactid"),
                        NumberOfChildren = c.GetAttributeValue<int?>("numberofchildren"),
                        CreditOnHold = c.GetAttributeValue<bool?>("creditonhold"),
                        Anniversary = c.GetAttributeValue<DateTime?>("anniversary"),
                       };

 foreach (var c in query_getattrib)
 {
  System.Console.WriteLine(c.ContactId + " " + c.NumberOfChildren + 
   " " + c.CreditOnHold + " " + c.Anniversary);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_getattrib = From c In svcContext.ContactSet _
                       Where Not c.GetAttributeValue(Of Guid)("contactid").Equals( _
                        _contactId1) _
                       Select New With
                              {Key .ContactId =
                                  c.GetAttributeValue(Of Guid?)("contactid"),
                               Key .NumberOfChildren =
                               c.GetAttributeValue(Of Integer?)("numberofchildren"),
                               Key .CreditOnHold =
                               c.GetAttributeValue(Of Boolean?)("creditonhold"),
                               Key .Anniversary =
                               c.GetAttributeValue(Of Date?)("anniversary")}

 For Each c In query_getattrib
  Console.WriteLine(c.ContactId.ToString() & " " _
                    & c.NumberOfChildren & " " & c.CreditOnHold _
                    & " " & c.Anniversary)
 Next c
End Using

Utiliser les méthodes Math

L’exemple suivant montre comment utiliser différentes méthodes Math.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_math = from c in svcContext.ContactSet
                  where c.ContactId != _contactId2
                  && c.Address1_Latitude != null && 
                  c.Address1_Longitude != null
                  select new
                  {
                   Round = Math.Round(c.Address1_Latitude.Value),
                   Floor = Math.Floor(c.Address1_Latitude.Value),
                   Ceiling = Math.Ceiling(c.Address1_Latitude.Value),
                   Abs = Math.Abs(c.Address1_Latitude.Value),
                  };
 foreach (var c in query_math)
 {
  System.Console.WriteLine(c.Round + " " + c.Floor + 
   " " + c.Ceiling + " " + c.Abs);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_math = From c In svcContext.ContactSet _
                  Where Not c.ContactId.Value.Equals(_contactId2) _
                  AndAlso c.Address1_Latitude IsNot Nothing _
                  AndAlso c.Address1_Longitude IsNot Nothing _
                  Select New With
                         {Key .Round =
                             Math.Round(c.Address1_Latitude.Value),
                          Key .Floor =
                             Math.Floor(c.Address1_Latitude.Value),
                          Key .Ceiling =
                             Math.Ceiling(c.Address1_Latitude.Value),
                          Key .Abs =
                             Math.Abs(c.Address1_Latitude.Value)}
 For Each c In query_math
  Console.WriteLine(c.Round & " " & c.Floor & " " _
                    & c.Ceiling & " " & c.Abs)
 Next c
End Using

Utiliser plusieurs clauses Select et Where

L’exemple suivant illustre plusieurs clauses Select et Where avec une syntaxe de requête basée sur une méthode.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_multiselect = svcContext.IncidentSet
                        .Where(i => i.IncidentId != _incidentId1)
                        .Select(i => i.incident_customer_accounts)
                        .Where(a => a.AccountId != _accountId2)
                        .Select(a => a.account_primary_contact)
                        .OrderBy(c => c.FirstName)
                        .Select(c => c.ContactId);
 foreach (var c in query_multiselect)
 {
  System.Console.WriteLine(c.GetValueOrDefault());
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_multiselect =
     svcContext.IncidentSet _
     .Where(Function(i) Not i.IncidentId.Value.Equals(_incidentId1)) _
     .Select(Function(i) i.incident_customer_accounts) _
     .Where(Function(a) Not a.AccountId.Value.Equals(_accountId2)) _
     .Select(Function(a) a.account_primary_contact) _
     .OrderBy(Function(c) c.FirstName).Select(Function(c) c.ContactId)
 For Each c In query_multiselect
  Console.WriteLine(c.GetValueOrDefault())
 Next c
End Using

Utiliser SelectMany

L’exemple suivant montre comment utiliser la méthode SelectMany.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_selectmany = svcContext.ContactSet
                        .Where(c => c.ContactId != _contactId2)
                        .SelectMany(c => c.account_primary_contact)
                        .OrderBy(a => a.Name);
 foreach (var c in query_selectmany)
 {
  System.Console.WriteLine(c.AccountId + " " + c.Name);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_selectmany =
     svcContext.ContactSet _
     .Where(Function(c) Not c.ContactId.Value.Equals(_contactId2)) _
     .SelectMany(Function(c) c.account_primary_contact) _
     .OrderBy(Function(a) a.Name)
 For Each c In query_selectmany
  Console.WriteLine(c.AccountId.ToString() & " " & c.Name)
 Next c
End Using

Utiliser les opérations de chaîne

L’exemple suivant montre comment utiliser différentes méthodes String.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_string = from c in svcContext.ContactSet
                    where c.ContactId == _contactId2
                    select new
                    {
                     IndexOf = c.FirstName.IndexOf("contact"),
                     Insert = c.FirstName.Insert(1, "Insert"),
                     Remove = c.FirstName.Remove(1, 1),
                     Substring = c.FirstName.Substring(1, 1),
                     ToUpper = c.FirstName.ToUpper(),
                     ToLower = c.FirstName.ToLower(),
                     TrimStart = c.FirstName.TrimStart(),
                     TrimEnd = c.FirstName.TrimEnd(),
                    };

 foreach (var c in query_string)
 {
  System.Console.WriteLine(c.IndexOf + "\n" + c.Insert + "\n" + 
   c.Remove + "\n" + c.Substring + "\n"
                           + c.ToUpper + "\n" + c.ToLower + 
                           "\n" + c.TrimStart + " " + c.TrimEnd);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_string = From c In svcContext.ContactSet _
                    Where c.ContactId.Value.Equals(_contactId2) _
                    Select New With
                           {Key .IndexOf = c.FirstName.IndexOf("contact"),
                            Key .Insert = c.FirstName.Insert(1, "Insert"),
                            Key .Remove = c.FirstName.Remove(1, 1),
                            Key .Substring = c.FirstName.Substring(1, 1),
                            Key .ToUpper = c.FirstName.ToUpper(),
                            Key .ToLower = c.FirstName.ToLower(),
                            Key .TrimStart = c.FirstName.TrimStart(),
                            Key .TrimEnd = c.FirstName.TrimEnd()}

 For Each c In query_string
  Console.WriteLine(c.IndexOf & vbLf & c.Insert & vbLf _
                    & c.Remove & vbLf & c.Substring & vbLf _
                    & c.ToUpper & vbLf & c.ToLower & vbLf _
                    & c.TrimStart & " " & c.TrimEnd)
 Next c
End Using

Utiliser deux clauses Where

L’exemple suivant montre comment utiliser deux clauses Where.

using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
 var query_twowhere = from a in svcContext.AccountSet
                      join c in svcContext.ContactSet 
                      on a.PrimaryContactId.Id equals c.ContactId
                      where c.LastName == "Smith" && c.CreditOnHold != null
                      where a.Name == "Contoso Ltd"
                      orderby a.Name
                      select a;
 foreach (var c in query_twowhere)
 {
  System.Console.WriteLine(c.AccountId + " " + c.Name);
 }
}

Using svcContext As New ServiceContext(_serviceProxy)
 Dim query_twowhere = From a In svcContext.AccountSet _
                      Join c In svcContext.ContactSet _
                      On a.PrimaryContactId.Id Equals c.ContactId _
                      Where c.LastName.Equals("Smith") _
                      AndAlso c.CreditOnHold IsNot Nothing _
                      Where a.Name.Equals("Contoso Ltd") _
                      Order By a.Name _
                      Select a
 For Each c In query_twowhere
  Console.WriteLine(c.AccountId.ToString() & " " & c.Name)
 Next c
End Using

Utiliser LoadProperty pour récupérer des enregistrements associés

L’exemple suivant montre comment utiliser LoadProperty pour accéder aux enregistrements associés.

Contact benAndrews = svcContext.ContactSet.Where(c => c.FullName == "Ben Andrews").FirstOrDefault();
if (benAndrews != null)
{
 //benAndrews.Contact_Tasks is null until LoadProperty is used.
 svcContext.LoadProperty(benAndrews, "Contact_Tasks");
 Task benAndrewsFirstTask = benAndrews.Contact_Tasks.FirstOrDefault();
 if (benAndrewsFirstTask != null)
 {
  Console.WriteLine("Ben Andrews first task with Subject: '{0}' retrieved.", benAndrewsFirstTask.Subject);
 }
}

Voir aussi

Générer des requêtes avec LINQ (Language-Integrated Query .NET)
Exemple : Créer une requête LINQ

Microsoft Dynamics 365

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