LINQ query examples
Applies To: Dynamics 365 (online), Dynamics 365 (on-premises), Dynamics CRM 2016, Dynamics CRM Online
This topic contains many samples of LINQ queries. For the full sample, see Sample: Complex LINQ queries.
In This Topic
Simple Where clause
Join and simple Where clause
Use the Distinct Operator
Simple inner join
Self-join
Double and multiple joins
Join using entity fields
Late-binding left join
Use the Equals operator
Use the Not Equals operator
Use a method-based LINQ query with a Where clause
Use the Greater Than operator
Use the Greater Than or Equals and Less Than or Equals operators
Use the Contains operator
Use the Does Not Contain operator
Use the StartsWith and EndsWith operators
Use the And and Or operators
Use the OrderBy operator
Use the First and Single operators
Retrieving formatted values
Use the Skip and Take operators without paging
Use the FirstOrDefault and SingleOrDefault operators
Use a self-join with a condition on the linked entity
Use a transformation in the Where Clause
Use a paging sort
Retrieve related entity columns for 1 to N relationships
Use .value to retrieve the value of an attribute
Multiple projections, new data type casting to different types
Use the GetAttributeValue method
Use Math methods
Use Multiple Select and Where clauses
Use SelectMany
Use string operations
Use two Where clauses
Use LoadProperty to retrieve related records
Simple Where clause
The following sample shows how to retrieve a list of accounts where the Name contains “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
The following sample shows how to retrieve a list of accounts where the Name contains “Contoso” and Address1_City is “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
Join and simple Where clause
The following sample shows how to retrieve the account Name and the contact LastName where the account Name contains “Contoso” and the contact LastName contains “Smith” and the contact is the Primary Contact for the account.
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
Use the Distinct Operator
The following sample shows how to retrieve a distinct list of contact last names. Although there may be duplicates, each name will be listed only once.
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
Simple inner join
The following sample shows how to retrieve information about an account and the contact listed as the primary contact for the account.
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
Self-join
The following sample shows how to retrieve information about accounts where an account is the parent account for an account.
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
Double and multiple joins
The following sample shows how to retrieve information from account, contact and lead where the contact is the primary contact for the account and the lead was the originating lead for the account.
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
The following sample shows how to retrieve account and contact information where an account is the parent account for an account and the contact is the primary contact for the account.
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
Join using entity fields
The following sample shows how to retrieve information about accounts from a list
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
Late-binding left join
The following sample shows a left join. A left join is designed to return parents with and without children from two sources. There is a correlation between parent and child, but no child may actually exist.
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
Use the Equals operator
The following sample shows how to retrieve a list of contacts where the FirstName is “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
The following sample shows how to retrieve a list of contacts where the FamilyStatusCode is 3. This corresponds to the Marital Status option of Divorced.
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
Use the Not Equals operator
The following sample shows how to retrieve a list of contacts where the Address1_City is not “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
The following sample shows how to retrieve a list of contacts where the FirstName is not “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
Use a method-based LINQ query with a Where clause
The following sample shows how to retrieve a list of contacts where the LastName is “Smith” or contains “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
Use the Greater Than operator
The following sample shows how to retrieve a list of contacts with an Anniversary date later than February 5, 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
The following sample shows how to retrieve contacts with a CreditLimit greater than $20,000.
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
Use the Greater Than or Equals and Less Than or Equals operators
The following sample shows how to retrieve contacts with a CreditLimit greater than $200 and less than $400.
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 & " " & c.LastName)
Next c
End Using
Use the Contains operator
The following sample shows how to retrieve contacts where the Description contains “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
Use the Does Not Contain operator
The following sample shows how to retrieve contacts where the Description does not contain “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
Use the StartsWith and EndsWith operators
The following sample shows how to retrieve contacts where FirstName starts with “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
The following sample shows how to retrieve contacts where LastName ends with “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
Use the And and Or operators
The following sample shows how to retrieve contacts where Address1_City is “Redmond” or “Bellevue” and a CreditLimit that is greater than $200.
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
Use the OrderBy operator
The following sample shows how to retrieve contacts ordered by CreditLimit in descending order.
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
The following sample shows how to retrieve contacts ordered by LastName in descending order and FirstName in ascending order.
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
Use the First and Single operators
The following sample shows how to retrieve only the first contact record returned and retrieve only one contact record that matches the criterion.
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
Retrieving formatted values
The following sample shows how to retrieve the label for an optionset option, in this case the value for the current record status.
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
Use the Skip and Take operators without paging
The following sample shows how to retrieve just two records after skipping two records where the LastName is not “Parker” using the Skip and Takeoperators.
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
Use the FirstOrDefault and SingleOrDefault operators
The FirstOrDefault operator returns the first element of a sequence, or a default value if no element is found. The SingleOrDefault operator returns a single, specific element of a sequence, or a default value if that element is not found. The following sample shows how to use these operators.
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
Use a self-join with a condition on the linked entity
The following sample shows how to retrieve the names of two accounts where one account is the parent account of the other.
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
Use a transformation in the Where Clause
The following sample shows how to retrieve a specific contact where the anniversary date is later than January 1, 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
Use a paging sort
The following sample shows a multi-column sort with an extra condition.
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
The following sample shows a paging sort where the column being sorted is different from the column being retrieved.
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
The following sample shows how to retrieve just the first 10 records.
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
Retrieve related entity columns for 1 to N relationships
The following sample shows how to retrieve columns from related account and contact records.
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
Use .value to retrieve the value of an attribute
The following sample shows usage of Value to access the value of an attribute.
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
Multiple projections, new data type casting to different types
The following sample shows multiple projections and how to cast values to a different 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
Use the GetAttributeValue method
The following sample shows how to use the GetAttributeValue<T> method.
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
Use Math methods
The following sample shows how to use various Math methods.
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
Use Multiple Select and Where clauses
The following sample shows multiple select and where clauses using a method-based query syntax.
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
Use SelectMany
The following sample shows how to use the SelectMany Method.
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
Use string operations
The following sample shows how to use various String methods.
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
Use two Where clauses
The following sample shows how to use two Where clauses.
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
Use LoadProperty to retrieve related records
The following sample shows how to LoadProperty to access related records.
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);
}
}
See Also
Build queries with LINQ (.NET language-integrated query)
Sample: Create a LINQ query
Microsoft Dynamics 365
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