private Boolean checkAndSyncSchema(Class<?> c, Connection connection) throws SQLException{
		
		if(!alreadyChecked.contains(c)){
			try {
				makeCreateTable(c, connection);
			} catch (SQLException e) {
				if(e.getMessage().indexOf("already exists") != -1){
					makeAlterTable(c, connection);
				}else{
					throw e;
				}
			}
		}
		alreadyChecked.add(c);
		return true;
	}