static void EntityClientDemo()
{
string connectionString = ConfigurationManager.ConnectionStrings["BooksEntities"].ConnectionString;
var connection = new EntityConnection(connectionString);
connection.Open();
EntityCommand command = connection.CreateCommand();
command.CommandText = "[BooksEntities].[Books]";
// command.CommandText = "SELECT Books.Title, Books.Publisher FROM [BooksEntities].[Books]";
// command.CommandText = "SELECT VALUE it FROM BooksEntities.Books AS it WHERE it.Publisher = @Publisher";
command.Parameters.AddWithValue("Publisher", "Wrox Press");
EntityDataReader reader = command.ExecuteReader(CommandBehavior.CloseConnection | CommandBehavior.SequentialAccess);
while (reader.Read())
{
Console.WriteLine("{0}, {1}", reader["Title"], reader["Publisher"]);
}
reader.Close();
}
private void ActDataTable_Click(System.Object sender, System.EventArgs e)
{
// ----- Query that returns an ADO.NET DataTable.
DataRow oneRow;
DataTable resultsAsTable;
EntityCommand query;
EntityDataReader results = null;
string sqlText;
// ----- Clear any previous results.
DisplayResults.DataSource = null;
// ----- Build a storage area for the results.
resultsAsTable = new DataTable();
resultsAsTable.Columns.Add("CustomerID", typeof(long));
resultsAsTable.Columns.Add("CustomerName", typeof(string));
resultsAsTable.Columns.Add("AnnualFee", typeof(decimal));
// ----- Connect to the entity provider.
using (EntityConnection linkToDB = new EntityConnection(GetConnectionString()))
{
try
{
linkToDB.Open();
}
catch (Exception ex)
{
MessageBox.Show("Error opening the data connection: " + ex.Message);
return;
}
// ----- Retrieve the data via a parameterized query.
try
{
}
catch (Exception ex)
{
MessageBox.Show("Error processing parameterized query: " + ex.Message);
return;
}
try
{
// ----- Move each row into the DataTable.
}
catch (Exception ex)
{
MessageBox.Show("Error saving query results: " + ex.Message);
return;
}
finally
{
results.Close();
}
// ----- Display the results to the user.
try
{
DisplayResults.DataSource = resultsAsTable;
MessageBox.Show(resultsAsTable.Rows.Count + " result(s)");
}
catch (Exception ex)
{
MessageBox.Show("Error displaying query results: " + ex.Message);
}
}
}
private void ActDataTable_Click(System.Object sender, System.EventArgs e)
{
// ----- Query that returns an ADO.NET DataTable.
DataRow oneRow;
DataTable resultsAsTable;
EntityCommand query;
EntityDataReader results = null;
string sqlText;
// ----- Clear any previous results.
DisplayResults.DataSource = null;
// ----- Build a storage area for the results.
resultsAsTable = new DataTable();
resultsAsTable.Columns.Add("CustomerID", typeof(long));
resultsAsTable.Columns.Add("CustomerName", typeof(string));
resultsAsTable.Columns.Add("AnnualFee", typeof(decimal));
// ----- Connect to the entity provider.
using (EntityConnection linkToDB = new EntityConnection(GetConnectionString()))
{
try
{
linkToDB.Open();
}
catch (Exception ex)
{
MessageBox.Show("Error opening the data connection: " + ex.Message);
return;
}
// ----- Retrieve the data via a parameterized query.
sqlText = @"SELECT CU.ID, CU.FullName, CU.AnnualFee
FROM SalesOrderEntities.Customers AS CU
WHERE CU.AnnualFee >= @MinFee ORDER BY CU.FullName";
try
{
query = new EntityCommand(sqlText, linkToDB);
query.Parameters.AddWithValue("MinFee", 200);
results = query.ExecuteReader(CommandBehavior.SequentialAccess);
}
catch (Exception ex)
{
MessageBox.Show("Error processing parameterized query: " + ex.Message);
return;
}
try
{
// ----- Move each row into the DataTable.
while (results.Read())
{
oneRow = resultsAsTable.NewRow();
oneRow["CustomerID"] = (long)results["ID"];
oneRow["CustomerName"] = (string)results["FullName"];
oneRow["AnnualFee"] = (decimal)results["AnnualFee"];
resultsAsTable.Rows.Add(oneRow);
}
}
catch (Exception ex)
{
MessageBox.Show("Error saving query results: " + ex.Message);
return;
}
finally
{
results.Close();
}
// ----- Display the results to the user.
try
{
DisplayResults.DataSource = resultsAsTable;
MessageBox.Show(resultsAsTable.Rows.Count + " result(s)");
}
catch (Exception ex)
{
MessageBox.Show("Error displaying query results: " + ex.Message);
}
}
}