/// <summary>
/// Executes a single command against a MySQL database, possibly inside an existing transaction.
/// </summary>
/// <param name="connection"><see cref="MySqlConnection"/> object to use for the command</param>
/// <param name="transaction"><see cref="MySqlTransaction"/> object to use for the command</param>
/// <param name="commandText">Command text to use</param>
/// <param name="commandParameters">Array of <see cref="MySqlParameter"/> objects to use with the command</param>
/// <param name="ExternalConn">True if the connection should be preserved, false if not</param>
/// <returns><see cref="MySqlDataReader"/> object ready to read the results of the command</returns>
private static MySqlDataReader ExecuteReader(MySqlConnection connection, MySqlTransaction transaction, string commandText, MySqlParameter[] commandParameters, bool ExternalConn )
{
//create a command and prepare it for execution
MySqlCommand cmd = new MySqlCommand();
cmd.Connection = connection;
cmd.Transaction = transaction;
cmd.CommandText = commandText;
cmd.CommandType = CommandType.Text;
if (commandParameters != null)
foreach (MySqlParameter p in commandParameters)
cmd.Parameters.Add( p );
//create a reader
MySqlDataReader dr;
// call ExecuteReader with the appropriate CommandBehavior
if (ExternalConn)
{
dr = cmd.ExecuteReader();
}
else
{
dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
// detach the SqlParameters from the command object, so they can be used again.
cmd.Parameters.Clear();
return dr;
}
/// <summary>
///
/// </summary>
/// <param name="level"></param>
/// <returns></returns>
public MySqlTransaction BeginTransaction(IsolationLevel level)
{
if (state != ConnectionState.Open)
throw new MySqlException("Invalid operation: The connection is closed");
MySqlTransaction t = new MySqlTransaction();
t.Connection = this;
t.IsolationLevel = level;
string cmd = "SET SESSION TRANSACTION ISOLATION LEVEL ";
switch (level)
{
case IsolationLevel.ReadCommitted:
cmd += "READ COMMITTED"; break;
case IsolationLevel.ReadUncommitted:
cmd += "READ UNCOMMITTED"; break;
case IsolationLevel.RepeatableRead:
cmd += "REPEATABLE READ"; break;
case IsolationLevel.Serializable:
cmd += "SERIALIZABLE"; break;
case IsolationLevel.Chaos:
throw new NotSupportedException("Chaos isolation level is not supported");
}
InternalConnection.Driver.Send( DBCmd.QUERY, cmd );
InternalConnection.Driver.Send( DBCmd.QUERY, "BEGIN");
return t;
}
/// <summary>
/// Overloaded. Initializes a new instance of the MySqlCommand class.
/// </summary>
public MySqlCommand(string cmdText, MySqlConnection connection, MySqlTransaction txn)
{
this.cmdText = cmdText;
this.connection = connection;
curTransaction = txn;
}
/// <summary>
/// Begins a database transaction.
/// </summary>
/// <returns></returns>
public MySqlTransaction BeginTransaction()
{
if (state != ConnectionState.Open)
throw new MySqlException("Invalid operation: The connection is closed");
MySqlTransaction t = new MySqlTransaction();
t.Connection = this;
InternalConnection.Driver.Send( DBCmd.QUERY, "BEGIN");
return t;
}