/// <summary>
/// Update the changes to the data at the server side
/// </summary>
/// <param name="context">The DataServiceContext to be updated.
/// </param>
/// <returns>Whether the update is successful.</returns>
private static bool UpdateData(DataServiceContext context)
{
try
{
// Get the response from the DataServiceContext update
// operation
DataServiceResponse response = context.SaveChanges();
bool isSucess = false;
foreach (var r in response)
{
// If response status code shows the update fails
// return false
if (!r.StatusCode.ToString().StartsWith("2"))
{
return(false);
}
else
{
isSucess = true;
}
}
// The update is successful
return(isSucess);
}
catch (Exception ex)
{
// Retrieve the exception information if there is some
// DataServiceException is thrown at the server side
if (ex.InnerException is DataServiceClientException)
{
// Parse the DataServieClientException
InnerDataServiceException innerException =
ParseDataServiceClientException(ex.InnerException.
Message);
// Display the DataServiceClientException message
if (innerException != null)
{
Console.WriteLine("DataServiceException Message: " +
innerException.Message);
}
}
else
{
Console.WriteLine("The update operation throws the error: "
+ ex.Message);
}
return(false);
}
}
static void Main(string[] args)
{
try
{
// Update and query relational database via LINQ to Entities
UpdateQueryRelationalDataByLinqToEntities();
// Update and query relational database via LINQ to SQL
UpdateQueryRelationDataByLinqToSQL();
// Query relational database via ADO.NET query options and
// custom service operations
QueryRelationDataByQueryOptionsAndServiceOperations();
// Insert and query non-relational data
UpdateQueryNonRelationalData();
}
catch (Exception ex)
{
// Retrieve the exception information if there is some
// DataServiceException is thrown at the server side
if (ex.InnerException is DataServiceClientException)
{
// Parse the DataServieClientException
InnerDataServiceException innerException =
ParseDataServiceClientException(ex.InnerException.
Message);
// Display the DataServiceClientException message
if (innerException != null)
{
Console.WriteLine("DataServiceException Message: " +
innerException.Message);
}
}
else
{
Console.WriteLine("The application throws the error: " +
ex.Message);
}
}
finally
{
Console.ReadLine();
}
}
/// <summary>
/// Update and query relational database via LINQ to Entities
/// </summary>
private static void UpdateQueryRelationalDataByLinqToEntities()
{
Console.WriteLine("======================================");
Console.WriteLine("Update and query data via LINQ to Entities:");
Console.WriteLine("======================================");
/////////////////////////////////////////////////////////////////
// Initialize the DataService object for ADO.NET Entity Data
// Model
//
SchoolLinqToEntitiesService.SQLServer2005DBEntities svc = new
SchoolLinqToEntitiesService.SQLServer2005DBEntities(new Uri(
schoolLinqToEntitiesUri));
/////////////////////////////////////////////////////////////////
// Insert wrong data which the server side handles
//
// Create a wrong instructor
SchoolLinqToEntitiesService.Person wrongInstructor = new
SchoolLinqToEntitiesService.Person()
{
FirstName = "Riquel",
LastName = "Dong",
HireDate = DateTime.Now,
// Set invalid value for the PersonCategory
PersonCategory = 3
};
Console.Write("Insert wrong Person information into database...");
// Update the changes to the database
if (UpdateData(svc))
{
Console.WriteLine("Successfully!");
}
else
{
Console.WriteLine("Failed!");
try
{
// Get the person update exception
svc.Execute <SchoolLinqToEntitiesService.Person>(new Uri(
"/GetPersonUpdateException", UriKind.Relative));
}
catch (Exception updateException)
{
// Retrieve the exception information if there is some
// DataServiceException is thrown at the server side
if (updateException.InnerException is
DataServiceClientException)
{
// Parse the DataServieClientException
InnerDataServiceException innerException =
ParseDataServiceClientException(
updateException.InnerException.Message);
// Display the DataServiceClientException message
if (innerException != null)
{
Console.WriteLine("DataServiceException Message: "
+ innerException.Message);
}
}
}
// Detach the incorrect Person object
svc.Detach(wrongInstructor);
}
/////////////////////////////////////////////////////////////////
// Insert relational data into database
//
// Create a new instructor
SchoolLinqToEntitiesService.Person newInstructor = new
SchoolLinqToEntitiesService.Person()
{
FirstName = "Riquel",
LastName = "Dong",
HireDate = DateTime.Now,
PersonCategory = 2
};
// Create a new course
SchoolLinqToEntitiesService.Course newCourse1 = new
SchoolLinqToEntitiesService.Course()
{
CourseID = 5010,
Title = "Network",
Credits = 4,
DepartmentID = 1
};
// Create a new course
SchoolLinqToEntitiesService.Course newCourse2 = new
SchoolLinqToEntitiesService.Course()
{
CourseID = 5020,
Title = "Database",
Credits = 3,
DepartmentID = 1
};
// Add the newly-created instructor into context
svc.AddToPerson(newInstructor);
// Add the newly-created courses into context
svc.AddToCourse(newCourse1);
svc.AddToCourse(newCourse2);
// Add relationships to the newly-created instructor and courses
svc.AddLink(newCourse1, "Person", newInstructor);
svc.AddLink(newCourse2, "Person", newInstructor);
Console.Write("Insert related data into database...");
// Update the changes to the database
if (UpdateData(svc))
{
Console.WriteLine("Successfully!");
}
else
{
Console.WriteLine("Faild!");
}
Console.WriteLine();
/////////////////////////////////////////////////////////////////
// Query single data table via LINQ
//
// Get all the teachers whose first name is 'Roger'
// LINQ operator and ADO.NET Data Service query option comparison
// 'where'(LINQ) <==> 'filter'(Query Option)
var teachers = from p in svc.Person
where p.PersonCategory == 2 &&
p.FirstName == "Roger"
select p;
Console.WriteLine("All the teachers whose first name is 'Roger':");
// Display the query results
foreach (var t in teachers)
{
Console.WriteLine("{0} {1}", t.FirstName, t.LastName);
}
Console.WriteLine();
// Get the third and fourth newly-enrolled students
// LINQ operator and ADO.NET Data Service query option comparison
// 'where'(LINQ) <==> 'filter'(Query Option)
// 'orderby' (LINQ) <==> 'orderby' (Query Option)
// 'Skip' (LINQ) <=> 'skip' (Query Option)
// 'Take' (LINQ) <==> 'top' (Query Option)
var students = (from p in svc.Person
where p.PersonCategory == 1
orderby p.EnrollmentDate descending
select p).Skip(2).Take(2);
Console.WriteLine("The third and fourth newly-enrolled students:");
// Display the query results
foreach (var s in students)
{
Console.WriteLine("{0} {1}", s.FirstName, s.LastName);
}
Console.WriteLine();
/////////////////////////////////////////////////////////////////
// Query relational data tables via LINQ and custom service
// operation
//
// Get the instructors whose name is 'Riquel Dong'
var instructors = from p in svc.Person
where p.LastName == "Dong" &&
p.FirstName == "Riquel"
select p;
// Get all the courses that 'Riquel Dong' owns
foreach (var i in instructors)
{
// Call the service operation CoursesByPersonID to get the
// certain person's courses based on primary key PersonID
Uri uri = new Uri(String.Format("/CoursesByPersonID?ID={0}",
i.PersonID), UriKind.Relative);
// Exceute the URL to the retrieve the course list
var courses = svc.Execute <SchoolLinqToEntitiesService.Course>
(uri);
Console.WriteLine("The instructor {0}'s couses:",
i.FirstName + " " + i.LastName);
// Display the query results
foreach (var c in courses)
{
Console.WriteLine("Course Title: {0}, Credits: {1}",
c.Title, c.Credits);
}
}
Console.WriteLine();
}
