Source code for pyensae.sql.database_object

# coding: latin-1
:class:`Database <pyensae.sql.database_main.Database>`

from pyquickhelper.loghelper.flog import fLOG

module_odbc = None

[docs]class DatabaseObject: """ Methods for database related to object, see :class:`Database <pyensae.sql.database_main.Database>`. :githublink:`%|py|16` """
[docs] def fill_table_with_objects( self, tablename, iterator_on, check_existence=False, skip_exception=False): """ Fill a table of a database with object (from ``iterator_on``) following the interface: - a property ``schema_database`` which gives the schema - a property ``asrow`` which puts all values in a row - a property ``index`` which precises the index to unless it returns None - a property ``indexes`` which precises other indexes to create (optional) The property ``asrow`` must not include other objects, only their ids. If the table does not exists, it creates it. :param tablename: name of a table (created if it does not exists) :param iterator_on: iterator_on on StreamRSS object :param check_existence: avoid adding an element if it already exists (based on the index columns) :param skip_exception: skip exception while inserting an element The function do not check duplicate among elements sent in ``iterator_on``, it only checks duplicate between the new and the old ones (meaning in the database). :githublink:`%|py|38` """ schema = None index = None indexes = None for _ in iterator_on: schema = _.schema_database index = _.index try: indexes = _.indexes except Exception: pass break if schema is None: # nothing to do, it is empty return if tablename not in self.get_table_list(): fLOG("create table ", tablename) cursor = self.create_table(tablename, schema) if index is not None: self.create_index( index + "_" + tablename + "_index", tablename, [index], unique=True) if indexes is not None: for ind in indexes: if isinstance(ind, str): self.create_index( ind + "_" + tablename + "_index", tablename, [ind], unique=False) else: self.create_index( "_".join(ind) + "_" + tablename + "_index", tablename, ind, unique=False) ite = map(lambda m: m.asrow, iterator_on) self.append_values( ite, tablename, schema, cursor=cursor, skip_exception=skip_exception) else: if check_existence: if index is None: raise ValueError( "unable to check existence because index property is not set up") def enumerate_nodup(iterator): for it in iterator: val = it.__dict__[index] view = self.execute_view( "SELECT * FROM %s WHERE %s=\"%s\";" % (tablename, index, val)) if len(view) == 0: yield it ite = map(lambda m: m.asrow, enumerate_nodup(iterator_on)) self.append_values( ite, tablename, schema, cursor=None, skip_exception=skip_exception) else: ite = map(lambda m: m.asrow, iterator_on) self.append_values( ite, tablename, schema, cursor=None, skip_exception=skip_exception) self.commit()
[docs] def enumerate_objects(self, table, classObject): """ Iterator on objects assuming each row of a table is a object (classObject type). The classObject must have the following properties: - a staticmethod ``schema_database_read`` which gives the schema - the constructor must accept a constructor where parameter have the same name as the column names :param table: table name :param classObject: class object :return: iterator on object Example: :: for blog in db.enumerate_objects ("blogs", StreamRSS): #... :githublink:`%|py|136` """ schema = classObject.schema_database_read() for row in self.execute("SELECT * FROM %s" % table): di = {schema[i][0]: v for i, v in enumerate(row)} yield classObject(**di)