private void ActAnonymousType_Click(System.Object sender, System.EventArgs e)
{
// ----- Query that returns a custom (anonymous) type.
string sqlText;
ObjectQuery <DbDataRecord> query;
// ----- Clear any previous results.
DisplayResults.DataSource = null;
try
{
// ----- Retrieve the entity data via a query.
ActiveContext = new SalesOrderEntities(GetConnectionString());
sqlText = @"SELECT CU.FullName, OE.ID, OE.OrderDate, OE.Total
FROM Customers AS CU INNER JOIN
OrderEntries AS OE ON CU.ID = OE.Customer";
query = new ObjectQuery <DbDataRecord>(sqlText, ActiveContext);
// ----- Display the results to the user.
DisplayResults.DataSource = query;
MessageBox.Show(query.Count() + " result(s)");
}
catch (Exception ex)
{
MessageBox.Show("Error during anonymous record retrieval: " + ex.Message);
}
}
private void ActNavigationProperty_Click(System.Object sender, System.EventArgs e)
{
// ----- Query that includes use of a navagation property.
string sqlText;
ObjectQuery <DbDataRecord> query;
// ----- Clear any previous results.
DisplayResults.DataSource = null;
try
{
// ----- Retrieve the data by following the navigation property.
ActiveContext = new SalesOrderEntities(GetConnectionString());
sqlText = @"SELECT CU.FullName, CU.State.Abbreviation
FROM Customers AS CU";
query = new ObjectQuery <DbDataRecord>(sqlText, ActiveContext);
// ----- Display the results to the user.
DisplayResults.DataSource = query;
MessageBox.Show(query.Count() + " result(s)");
}
catch (Exception ex)
{
MessageBox.Show("Error during navigation property retrieval: " + ex.Message);
}
}
private void ActProcess_Click(System.Object sender, System.EventArgs e)
{
// ----- Let the user supply a custom query.
string sqlText;
ObjectQuery <DbDataRecord> query;
// ----- Check for a valid query.
if (CustomQuery.Text.Trim().Length == 0)
{
MessageBox.Show("Please supply a query.");
return;
}
// ----- Clear any previous results.
DisplayResults.DataSource = null;
try
{
// ----- Retrieve the custom query content.
ActiveContext = new SalesOrderEntities(GetConnectionString());
sqlText = CustomQuery.Text;
query = new ObjectQuery <DbDataRecord>(sqlText, ActiveContext);
// ----- Display the results to the user.
DisplayResults.DataSource = query;
MessageBox.Show(query.Count() + " result(s)");
}
catch (Exception ex)
{
MessageBox.Show("Error processing query: " + ex.Message);
}
}
private void ActSingleEntity_Click(System.Object sender, System.EventArgs e)
{
// ----- Query of single entity.
string sqlText;
ObjectQuery <Customer> query;
// ----- Clear any previous results.
DisplayResults.DataSource = null;
try
{
// ----- Retrieve the customer entities via a query.
ActiveContext = new SalesOrderEntities(GetConnectionString());
sqlText = @"SELECT VALUE Customer FROM Customers
AS Customer ORDER BY Customer.FullName DESC";
query = new ObjectQuery <Customer>(sqlText, ActiveContext);
// ----- Display the results to the user.
DisplayResults.DataSource = query;
MessageBox.Show(query.Count() + " result(s)");
}
catch (Exception ex)
{
MessageBox.Show("Error during single record retrieval: " + ex.Message);
}
}
private void ActSimpleRetrieval_Click(System.Object sender, System.EventArgs e)
{
// ----- Simple retrieval of all entities in a set.
ObjectSet <Customer> query;
// ----- Clear any previous results.
DisplayResults.DataSource = null;
try
{
// ----- Retrieve the customer entities directly.
ActiveContext = new SalesOrderEntities(GetConnectionString());
query = ActiveContext.CreateObjectSet <Customer>();
// ----- Display the results to the user.
DisplayResults.DataSource = query;
MessageBox.Show(query.Count() + "{0} result(s)");
}
catch (Exception ex)
{
MessageBox.Show("Error during record retrieval: " + ex.Message);
}
}
