/// <summary>
/// Cancels the specified command.
/// </summary>
/// <param name="command">The database command to cancel.</param>
protected void DatabaseQueryCancel(DbCommand command)
{
// Cancel the command.
command.Cancel();
// Call the event handler.
this.OnQueryCanceling(command.Query);
}
// Protected methods.
/// <summary>
/// A method called when the execution of the database query starts.
/// </summary>
/// <param name="server">The database server.</param>
/// <param name="query">The database query.</param>
/// <param name="command">The database command.</param>
protected virtual void OnQueryStarted(DbServerSql server, DbQuerySql query, DbCommand command)
{
}
/// <summary>
/// A method called when staring a query.
/// </summary>
/// <param name="server">The database server.</param>
/// <param name="query">The database query.</param>
/// <param name="command">The database command.</param>
protected override void OnQueryStarted(DbServerSql server, DbQuerySql query, DbCommand command)
{
// Disable the control.
this.tabControl.Enabled = false;
// Raise the database operation started event.
if (this.DatabaseOperationStarted != null) this.DatabaseOperationStarted(this, EventArgs.Empty);
}
/// <summary>
/// An event handler called when the refresh operation completed successfully and the resulting data is object
/// data.
/// </summary>
/// <param name="server">The database server.</param>
/// <param name="query">The database query.</param>
/// <param name="result">The database result.</param>
/// <param name="recordsAffected">The number of records affected.</param>
protected override void OnQuerySucceeded(DbServerSql server, DbQuerySql query, DbDataObject result, int recordsAffected)
{
// Set the current result.
this.result = result;
try
{
// Add the table rows.
for (int row = 0; row < this.result.RowCount; row++)
{
// Add the new row, and get the row index.
int index = this.dataGrid.Rows.Add(this.query.Table.GetValues(this.result[row]));
// Set the row tag with the table object.
this.dataGrid.Rows[index].Tag = result[row];
}
}
catch (Exception exception)
{
// If an exception occurs, call the refresh fail method.
this.OnQueryFailed(server, query, exception);
return;
}
// Set the current command to null.
this.command = null;
// Enable the buttons.
this.buttonRefresh.Enabled = true;
this.buttonCancel.Enabled = false;
this.buttonClose.Enabled = true;
// Update the status box.
this.labelStatus.Text = "{0} object{1} fetched.".FormatWith(result.RowCount, result.RowCount.PluralSuffix());
// Raise the database operation finished event.
if (this.DatabaseOperationFinished != null) this.DatabaseOperationFinished(this, EventArgs.Empty);
}
/// <summary>
/// A method called when the execution of the database query starts.
/// </summary>
/// <param name="server">The database server.</param>
/// <param name="query">The database query.</param>
/// <param name="command">The database command.</param>
protected override void OnQueryStarted(DbServerSql server, DbQuerySql query, DbCommand command)
{
// Save the current command.
this.command = command;
// Enable the cancel button.
this.buttonRefresh.Enabled = false;
this.buttonClose.Enabled = false;
this.buttonCancel.Enabled = true;
// Raise the database operation started event.
if (this.DatabaseOperationStarted != null) this.DatabaseOperationStarted(this, EventArgs.Empty);
}
/// <summary>
/// A method called when the executiopn of the database query has failed.
/// </summary>
/// <param name="server">The database server.</param>
/// <param name="query">The database query.</param>
/// <param name="exception">The exception.</param>
protected override void OnQueryFailed(DbServerSql server, DbQuerySql query, Exception exception)
{
// Enable the buttons.
this.buttonRefresh.Enabled = true;
this.buttonCancel.Enabled = false;
this.buttonClose.Enabled = true;
// Set the current command to null.
this.command = null;
// Update the status box.
this.labelStatus.Text = "Query failed. {0}".FormatWith(exception.Message);
// Raise the database operation finished event.
if (this.DatabaseOperationFinished != null) this.DatabaseOperationFinished(this, EventArgs.Empty);
}
/// <summary>
/// An event handler called when the user clicks on the start query button.
/// </summary>
/// <param name="sender">The sender object.</param>
/// <param name="e">The event arguments.</param>
private void OnStart(object sender, EventArgs e)
{
// Execute the code on the UI thread.
this.Invoke(() =>
{
// If the database server is not connected, first connect to the database.
if (this.server.State != DbServerSql.ServerState.Connected)
{
// Show a connecting message.
this.ShowMessage(Resources.Connect_48, "Database", "Connecting to the database server \'{0}\'...".FormatWith(this.server.Name));
try
{
// Connect asynchronously to the database server, and add this method as a handler.
this.server.Open(this.OnConnected, new EventHandler(this.OnStart));
}
catch (Exception exception)
{
// If an exception occurs, hide the connecting message.
this.HideMessage();
// Display an error message box to the user.
MessageBox.Show(
this,
"Connecting to the database server \'{0}\' failed. {1}".FormatWith(this.server.Name, exception.Message),
"Connecting to Database Failed",
MessageBoxButtons.OK,
MessageBoxIcon.Error
);
}
return;
}
// Refresh the list of databases.
// Create a new database command for the list of server databases.
try
{
// Clear the result table.
this.dataGrid.Rows.Clear();
this.dataGrid.Columns.Clear();
// Disable the start button.
this.buttonStart.Enabled = false;
// Enable the stop button.
this.buttonStop.Enabled = true;
// Disable the query code box.
this.codeBox.Enabled = false;
// Set the command to null.
this.command = null;
// Show a connecting message.
this.ShowMessage(Resources.DatabaseBusy_48, "Database", "Executing query on the database server \'{0}\'...".FormatWith(this.server.Name));
// Create the command.
this.command = this.server.CreateCommand(DbQuerySql.Create(this.codeBox.Text));
// Execute the command.
command.ExecuteReader((DbAsyncResult commandResult, DbReader reader) =>
{
try
{
// Throw the command exception, if any.
if (commandResult.Exception != null) throw commandResult.Exception;
// Read the results table.
reader.Read(null, (DbAsyncResult readerResult, DbDataRaw result) =>
{
try
{
// Throw the reader exception, if any.
if (readerResult.Exception != null)
{
reader.Close();
throw readerResult.Exception;
}
// Get the number of records affected.
int recordsAffected = reader.RecordsAffected;
// Close the reader.
reader.Close();
// Dispose and reset the command.
this.command.Dispose();
this.command = null;
// Show a success message.
this.ShowMessage(Resources.DatabaseSuccess_48, "Database", "Executing query on the database server \'{0}\' completed successfully.".FormatWith(this.server.Name), false);
// Wait.
Thread.Sleep(ApplicationConfig.MessageCloseDelay);
// Hide the message.
this.HideMessage();
// Call the completion method.
this.OnQuerySuccess(result, recordsAffected);
}
catch (Exception exception)
{
// Dispose and reset the command.
this.command.Dispose();
this.command = null;
// Show an error message.
this.ShowMessage(Resources.DatabaseError_48, "Database", "Executing query on the database server \'{0}\' failed.".FormatWith(this.server.Name), false);
// Log the event.
this.server.LogEvent(
LogEventLevel.Important,
LogEventType.Error,
"Executing query on the database server \'{0}\' failed. {1}",
new object[] { this.server.Name, exception.Message },
exception);
// Wait.
Thread.Sleep(ApplicationConfig.MessageCloseDelay);
// Hide the message.
this.HideMessage();
// Call the completion method.
this.OnQueryFail(exception);
}
});
}
catch (Exception exception)
{
// Dispose and reset the command.
this.command.Dispose();
this.command = null;
// Show an error message.
this.ShowMessage(Resources.DatabaseError_48, "Database", "Executing query on the database server \'{0}\' failed.".FormatWith(this.server.Name), false);
// Log the event.
this.server.LogEvent(
LogEventLevel.Important,
LogEventType.Error,
"Executing query on the database server \'{0}\' failed. {1}",
new object[] { this.server.Name, exception.Message },
exception);
// Wait.
Thread.Sleep(ApplicationConfig.MessageCloseDelay);
// Hide the message.
this.HideMessage();
// Call the completion method.
this.OnQueryFail(exception);
}
});
}
catch (Exception exception)
{
// Dispose and reset the command.
this.command.Dispose();
this.command = null;
// Show an error message.
this.ShowMessage(Resources.DatabaseError_48, "Database", "Executing query on the database server \'{0}\' failed.".FormatWith(this.server.Name), false);
// Log the event.
this.server.LogEvent(
LogEventLevel.Important,
LogEventType.Error,
"Executing query on the database server \'{0}\' failed. {1}",
new object[] { this.server.Name, exception.Message },
exception);
// Wait.
Thread.Sleep(ApplicationConfig.MessageCloseDelay);
// Hide the message.
this.HideMessage();
// Call the completion method.
this.OnQueryFail(exception);
}
});
}