The data isn't being loaded into datagrid view. What am i missing? - sql

Question

I think this is one of those times where I'm looking at the code and it all seems fine because my eye's think it will be. I need a fresh set of eyes to look at this code and tell me way it's not loading into the first datagrid view. Thank you for any help your able to provide.
private DataSet DataSetRentals { get; set; }
public DataRelationForm()
{
InitializeComponent();
}
private void DataRelationForm_Load(object sender, EventArgs e)
{
DataSet relationship = new DataSet("relationship");
/////
SqlConnection conn = Database.GetConnection();
SqlDataAdapter adapter = new SqlDataAdapter("Select * From Car", conn);
DataSet DataSetRentals = new DataSet("Relationship");
adapter.FillSchema(DataSetRentals, SchemaType.Source, "Car");
adapter.Fill(DataSetRentals, "Car");
adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
adapter.Fill(DataSetRentals, "Car");
DataTable Car;
Car = DataSetRentals.Tables["Car"];
foreach (DataRow drCurrent in Car.Rows)
{
Console.WriteLine("{0} {1}",
drCurrent["au_fname"].ToString(),
drCurrent["au_lname"].ToString());
}
////////////////////////////////////
SqlDataAdapter adapter2 = new SqlDataAdapter("Select * From CarRental", conn);
adapter.FillSchema(DataSetRentals, SchemaType.Source, "Rentals");
adapter.Fill(DataSetRentals, "Rentals");
adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
adapter.Fill(DataSetRentals, "Rentals");
DataTable CarRental;
CarRental = DataSetRentals.Tables["Rentals"];
foreach (DataRow drCurrent in CarRental.Rows)
{
Console.WriteLine("{0} {1}",
drCurrent["au_fname"].ToString(),
drCurrent["au_lname"].ToString());
}
/////
SqlDataAdapter adapter3 = new SqlDataAdapter("Select * From Customer", conn);
adapter.FillSchema(DataSetRentals, SchemaType.Source, "Customer");
adapter.Fill(DataSetRentals, "Customer");
adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
adapter.Fill(DataSetRentals, "Customer");
DataTable Customer;
Customer = DataSetRentals.Tables["Customer"];
foreach (DataRow drCurrent in Customer.Rows)
{
Console.WriteLine("{0} {1}",
drCurrent["au_fname"].ToString(),
drCurrent["au_lname"].ToString());
}
////////////////////////
DataSetRentals.Tables.Add(Customer);
DataSetRentals.Tables.Add(CarRental);
DataSetRentals.Tables.Add(Car);
DataRelation Step1 = new DataRelation("Customer2CarR",
Customer.Columns["CustomerNo"], CarRental.Columns["CustomerNo"]);
DataSetRentals.Relations.Add(Step1);
DataRelation Step2 = new DataRelation("CarR2Car",
Car.Columns["CarID"], CarRental.Columns["CarID"]);
DataSetRentals.Relations.Add(Step2);
////////////////////////
CustomerGrid.DataSource= DataSetRentals.Tables["Customer"];
CarRGrid.DataSource = DataSetRentals.Tables["CarRental"];
CarGrid.DataSource = DataSetRentals.Tables["Car"];
CustomerGrid.SelectionChanged += new EventHandler(Customer_SelectionChanged);
CarRGrid.SelectionChanged += new EventHandler(CarR_SelectionChanged);
}
private void Customer_SelectionChanged(Object sender, EventArgs e)
{
if (CustomerGrid.SelectedRows.Count > 0)
{
DataRowView selectedRow =
(DataRowView)CustomerGrid.SelectedRows[0].DataBoundItem;
DataSetRentals.Tables["CarRental"].DefaultView.RowFilter =
"CustomerNo = " + selectedRow.Row["CustomerNo"].ToString();
}
else
{
}
}
private void CarR_SelectionChanged(Object sender, EventArgs e)
{
if (CarRGrid.SelectedRows.Count > 0)
{
DataRowView selectedRow =
(DataRowView)CarRGrid.SelectedRows[0].DataBoundItem;
DataSetRentals.Tables["Car"].DefaultView.RowFilter =
"CarID = " + selectedRow.Row["CarID"].ToString();
}
}
And this is the code for the Database.GetConnection() method:
SqlConnectionStringBuilder stringBuilder = new SqlConnectionStringBuilder();
bool OnUni;
OnUni = (System.Environment.UserDomainName == "SOAC") ? true : false;
stringBuilder.DataSource = (OnUni) ? #"SOACSQLSERVER\SHOLESQLBSC" : "(local)";
stringBuilder.InitialCatalog = "CarRental_P117365";
stringBuilder.IntegratedSecurity = true;
return new SqlConnection(stringBuilder.ConnectionString);

Answer 1

It looks like you may have forgotten to call SqlConnection.Open() to actually open the connection. I would also recommend wrapping your connection in a using and explicitly calling SqlConnection.Close() at the end of it, so you don't accidentally leave it open:
using(SqlConnection conn = Database.GetConnection())
{
conn.Open();
/*
rest of code here
*/
conn.Close();
}
For some other good information/examples of properly opening/disposing of SqlConnections, you can also take a look at these SO questions:
Close and Dispose - which to call?
Do I have to Close() a SQLConnection before it gets disposed?
in a "using" block is a SqlConnection closed on return or exception?

Answer 2

youre not binding your data to any datasoruce.
try something like this
using(SqlConnection conn = Database.GetConnection())
try
{
{
------your code here up to DataTable Car-----
DataTable Car;
Car = DataSetRentals.Tables["Car"];
gridview.Datasource = Car;
}
}
catch (SqlException sqlex )
{
string msg = "Fetch Error:";
msg += sqlex.Message;
throw new Exception(msg);
}
Theres no need to open or close the SQL connection as this is done using the using statement at the top where it opens, and when its finishes closes \ disposes of the connection