private void Form1_Load(object sender, EventArgs e)
{
//
// As app starts up, ping SQL Server to start it running:
//
DataAccessTier.Data datatier = new DataAccessTier.Data(dbfilename);
try
{
datatier.TestConnection();
}
catch
{
// ignore since just pinging to start:
}
//
//Create Linq to SQL object context
//
db = new CoursemoEntities();
}
private void resetDatabaseToolStripMenuItem_Click(object sender, EventArgs e)
{
//
// Reset the database, i.e. delete all the rentals and
// set all bikes to *not* rented:
//
int retries = 0;
SqlConnection db = null;
SqlTransaction tx = null;
while (retries < 3)
{
try
{
db = new SqlConnection(connectioninfo);
db.Open();
tx = db.BeginTransaction(IsolationLevel.Serializable);
string sql = string.Format(@"
DELETE FROM StudentCourses; -- delete all StudentCourses:
DELETE FROM Waitlist; -- now delete all Waitlist items:
UPDATE Courses
Set NumEnrolled = 0;
");
//MessageBox.Show(sql);
SqlCommand cmd = new SqlCommand();
cmd.Connection = db;
cmd.CommandText = sql;
cmd.Transaction = tx;
//MessageBox.Show(sql);
int rowsModified = cmd.ExecuteNonQuery();
//Commit Transactions
tx.Commit();
//
// reset the GUI:
//
cmdLoadCourses_Click(sender, e);
cmdLoadStudents_Click(sender, e);
break;
}
catch (SqlException ex)
{
if (ex.Number == 1205)
{
retries++;
}
else
{
MessageBox.Show(ex.Message);
break;
}
}
catch (Exception ex)
{
if (tx != null)
{
tx.Rollback();
}
MessageBox.Show(ex.Message);
break;
}
finally
{
//MessageBox.Show("This is the Finally Satement");
if (db != null)
{
db.Close();
}
}
}
}