class MyIdentifiablePostgresPersistence(IdentifiablePostgresPersistence, IMyDataPersistence):

    def __init__(self):
        super().__init__('mydata')

    def _define_schema(self):
        self._clear_schema()
        self._ensure_schema('CREATE TABLE ' + self._table_name + ' (id TEXT PRIMARY KEY, key TEXT, content TEXT)')
        self._ensure_index(self._table_name + '_key', {'key': 1}, {'unique': True})

    def _compose_filter(self, filter: FilterParams):
        filter = filter or FilterParams()
        key = filter.get_as_nullable_string('key')
        content = filter.get_as_nullable_string('content')

        filter_condition = ''
        if key is not None:
            filter_condition += "key='" + key + "'"
        if content is not None:
            filter_condition += "content='" + content + "'"

        return filter_condition

    def _compose_sort(self, sort: SortParams):
        sort = sort or SortParams()
        compose_sort = ''

        for i, filed in enumerate(sort):
            compose_sort += filed.name + (' ASC' if filed.ascending else ' DESC')

        return compose_sort

    def get_page_by_filter(self, correlation_id: Optional[str], filter: FilterParams, paging: PagingParams,
                           sort: SortParams) -> DataPage:
        return super().get_page_by_filter(correlation_id, self._compose_filter(filter), paging,
                                          self._compose_sort(sort), None)

    def get_count_by_filter(self, correlation_id: Optional[str], filter: FilterParams) -> int:
        return super().get_count_by_filter(correlation_id, self._compose_filter(filter))

    def get_list_by_filter(self, correlation_id: Optional[str], filter: FilterParams, sort: SortParams) -> List[MyData]:
        return super().get_list_by_filter(correlation_id, self._compose_filter(filter), self._compose_sort(sort), None)

    def get_one_random(self, correlation_id: Optional[str], filter: FilterParams) -> MyData:
        return super().get_one_random(correlation_id, self._compose_filter(filter))

    def delete_by_filter(self, correlation_id: Optional[str], filter: FilterParams):
        return super().delete_by_filter(correlation_id, self._compose_filter(filter))