LINQ query examples using OrganizationServiceContext with Microsoft Dataverse
This topic contains many code samples of LINQ queries.
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
Join using table column 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);
}
}
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);
}
}
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);
}
}
The following sample shows how to retrieve a list of contacts where the FamilyStatusCode is 3. This corresponds to the Marital Status choice 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);
}
}
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);
}
}
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);
}
}
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"]);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
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);
}
}
Use the First and Single operators
The following sample shows how to retrieve only the first contact row returned and retrieve only one contact row 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");
}
Retrieving formatted values
The following sample shows how to retrieve the label for a choices option, in this case the value for the current row.
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);
}
}
Use the Skip and Take operators without paging
The following sample shows how to retrieve just two rows after skipping two rows 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);
}
}
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");
}
Use a self-join with a condition on the linked table row
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);
}
}
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);
}
}
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);
}
}
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);
}
}
The following sample shows how to retrieve just the first 10 rows.
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);
}
}
Retrieve related table row columns for 1 to N relationships
The following sample shows how to retrieve columns from related account and contact rows.
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);
}
}
Use .value to retrieve the value of a column (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);
}
}
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);
}
}
Use the GetAttributeValue method
The following sample shows how to use the GetAttributeValue<T>(String) 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);
}
}
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);
}
}
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());
}
}
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);
}
}
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);
}
}
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);
}
}
Use LoadProperty to retrieve related rows
The following sample shows how to call LoadProperty(Entity, Relationship) to access related rows.
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);
}
}