private void initQuery(QueryType queryType)
	{
		switch (queryType)
		{
			case DELETE:
				if (this.deleteQuery == null)
				{
					this.deleteQuery = new DeleteQuery(_db);
				}
				break;
			case SELECT:
				if (this.selectQuery == null)
				{
					this.selectQuery = new SelectQuery(_db);
				}
				break;
			case UPDATE:
				if (this.updateQuery == null)
				{
					this.updateQuery = new UpdateQuery(_db);
				}
				break;
			case INSERT:
				if (this.insertQuery == null)
				{
					this.insertQuery = new InsertQuery(_db);
				}
				break;
		}
	}