sqlalchemy.orm aliased Example Code

aliased is a callable within the sqlalchemy.orm module of the SQLAlchemy project.

ColumnProperty, CompositeProperty, Load, Mapper, Query, RelationshipProperty, Session, SynonymProperty, attributes, backref, class_mapper, column_property, composite, interfaces, mapper, mapperlib, object_mapper, object_session, query, relationship, session, sessionmaker, and strategies are several other callables with code examples from the same sqlalchemy.orm package.

Example 1 from SQLAlchemy Mixins

SQLAlchemy Mixins (PyPI package information) is a collection of mixins useful for extending SQLAlchemy and simplifying your database-interacting code for some common use cases. SQLAlchemy Mixins is open sourced under the MIT license.

SQLAlchemy Mixins / sqlalchemy_mixins / smartquery.py

# smartquery.py
try:
    from typing import List
except ImportError:  # pragma: no cover
    pass

from collections import OrderedDict

import sqlalchemy
from sqlalchemy import asc, desc, inspect
from sqlalchemy.orm import aliased, contains_eager
from sqlalchemy.orm.util import AliasedClass
from sqlalchemy.sql import operators, extract

from .eagerload import _flatten_schema, _eager_expr_from_flat_schema, \
    EagerLoadMixin
from .inspection import InspectionMixin
from .utils import classproperty

RELATION_SPLITTER = '___'
OPERATOR_SPLITTER = '__'

DESC_PREFIX = '-'


def _parse_path_and_make_aliases(entity, entity_path, attrs, aliases):
    relations = {}
    for attr in attrs:
        if RELATION_SPLITTER in attr:
            relation_name, nested_attr = attr.split(RELATION_SPLITTER, 1)
            if relation_name in relations:
                relations[relation_name].append(nested_attr)
            else:
                relations[relation_name] = [nested_attr]

    for relation_name, nested_attrs in relations.items():
        path = entity_path + RELATION_SPLITTER + relation_name \
               if entity_path else relation_name
        if relation_name not in entity.relations:
            raise KeyError("Incorrect path `{}`: "
                           "{} doesnt have `{}` relationship "
                           .format(path, entity, relation_name))
        relationship = getattr(entity, relation_name)
        alias = aliased(relationship.property.mapper.class_)
        aliases[path] = alias, relationship
        _parse_path_and_make_aliases(alias, path, nested_attrs, aliases)


def smart_query(query, filters=None, sort_attrs=None, schema=None):
    if not filters:
        filters = {}
    if not sort_attrs:
        sort_attrs = []
    if not schema:
        schema = {}

    root_cls = query._entity_zero().class_  # for example, User or Post
    attrs = list(filters.keys()) + \
        list(map(lambda s: s.lstrip(DESC_PREFIX), sort_attrs))
    aliases = OrderedDict({})
    _parse_path_and_make_aliases(root_cls, '', attrs, aliases)

    loaded_paths = []
    for path, al in aliases.items():
        relationship_path = path.replace(RELATION_SPLITTER, '.')
        query = query.outerjoin(al[0], al[1]) \
            .options(contains_eager(relationship_path, alias=al[0]))
        loaded_paths.append(relationship_path)


## ... source file continues with no further aliased examples...

Sponsored By

Sentry logo

Software errors are inevitable. Chaos is not. Try Sentry for free.


AssemblyAI logo

The most accurate speech-to-text API. Built for Python developers.

1. Introduction 2. Development Environments 3. Data 4. Web Development 5. Deployment 6. DevOps Changelog What Full Stack Means About the Author Future Directions Page Statuses SQLAlchemy ExtensionsSQLAlchemy Example CodeSQLAlchemy Modelssqlalchemy.databases mysqlsqlalchemy.dialects mssqlsqlalchemy.dialects mysqlsqlalchemy.dialects oraclesqlalchemy.schema DDLsqlalchemy.dialects postgresqlsqlalchemy.sql.expression Functionsqlalchemy.dialects sqlitesqlalchemy.dialects.mysql pymysqlsqlalchemy.dialects.postgresql ARRAYsqlalchemy.dialects.postgresql BIGINTsqlalchemy.dialects.postgresql BITsqlalchemy.dialects.postgresql DOUBLE_PRECISIONsqlalchemy.dialects.postgresql ExcludeConstraintsqlalchemy.dialects.postgresql INTEGERsqlalchemy.dialects.postgresql JSONsqlalchemy.dialects.postgresql TSVECTORsqlalchemy.dialects.postgresql pypostgresqlsqlalchemy.dialects.postgresql.base PGCompilersqlalchemy.dialects.postgresql.base PGIdentifierPreparersqlalchemy.dialects.postgresql.base PGTypeCompilersqlalchemy.dialects.postgresql.psycopg2 PGDialect_psycopg2sqlalchemy.dialects.sqlite pysqlitesqlalchemy.engine Connectionsqlalchemy.engine Enginesqlalchemy.engine create_enginesqlalchemy.engine defaultsqlalchemy.engine urlsqlalchemy.engine.default DefaultDialectsqlalchemy.engine.interfaces ExecutionContextsqlalchemy.engine.result ResultMetaDatasqlalchemy.engine.result RowProxysqlalchemy.engine.strategies EngineStrategysqlalchemy.engine.strategies MockEngineStrategysqlalchemy.engine.url make_urlsqlalchemy.events SchemaEventTargetsqlalchemy.exc ArgumentErrorsqlalchemy.exc DataErrorsqlalchemy.exc DatabaseErrorsqlalchemy.exc IntegrityErrorsqlalchemy.exc InvalidRequestErrorsqlalchemy.exc NoInspectionAvailablesqlalchemy.exc NoSuchTableErrorsqlalchemy.exc OperationalErrorsqlalchemy.exc ProgrammingErrorsqlalchemy.exc UnsupportedCompilationErrorsqlalchemy.ext compilersqlalchemy.ext.associationproxy AssociationProxysqlalchemy.ext.automap automap_basesqlalchemy.ext.compiler compilessqlalchemy.ext.declarative DeclarativeMetasqlalchemy.ext.declarative declarative_basesqlalchemy.ext.hybrid hybrid_methodsqlalchemy.ext.hybrid hybrid_propertysqlalchemy.ext.mutable Mutablesqlalchemy.inspection inspectsqlalchemy.orm ColumnPropertysqlalchemy.orm CompositePropertysqlalchemy.orm Loadsqlalchemy.orm Querysqlalchemy.orm RelationshipPropertysqlalchemy.orm SynonymPropertysqlalchemy.orm aliasedsqlalchemy.orm attributessqlalchemy.orm backrefsqlalchemy.orm class_mappersqlalchemy.orm column_propertysqlalchemy.orm compositesqlalchemy.orm interfacessqlalchemy.orm mappersqlalchemy.orm mapperlibsqlalchemy.orm object_mappersqlalchemy.orm object_sessionsqlalchemy.orm relationshipsqlalchemy.orm sessionsqlalchemy.orm sessionmakersqlalchemy.orm strategiessqlalchemy.orm.attributes InstrumentedAttributesqlalchemy.orm.attributes QueryableAttributesqlalchemy.orm.attributes flag_modifiedsqlalchemy.orm.collections InstrumentedListsqlalchemy.orm.exc NoResultFoundsqlalchemy.orm.exc UnmappedClassErrorsqlalchemy.orm.exc UnmappedInstanceErrorsqlalchemy.orm.interfaces MapperPropertysqlalchemy.orm.interfaces PropComparatorsqlalchemy.orm.mapper Mappersqlalchemy.orm.properties ColumnPropertysqlalchemy.orm.properties RelationshipPropertysqlalchemy.orm.query Querysqlalchemy.orm.query QueryContextsqlalchemy.orm.relationships RelationshipPropertysqlalchemy.orm.session Sessionsqlalchemy.orm.session object_sessionsqlalchemy.orm.util AliasedClasssqlalchemy.orm.util AliasedInspsqlalchemy.orm.util identity_keysqlalchemy.pool NullPoolsqlalchemy.pool StaticPoolsqlalchemy.schema CheckConstraintsqlalchemy.schema Columnsqlalchemy.schema CreateIndexsqlalchemy.schema CreateTablesqlalchemy.schema DDLElementsqlalchemy.schema ForeignKeysqlalchemy.schema ForeignKeyConstraintsqlalchemy.schema Indexsqlalchemy.schema PrimaryKeyConstraintsqlalchemy.schema Tablesqlalchemy.sql ClauseElementsqlalchemy.sql columnsqlalchemy.sql expressionsqlalchemy.sql extractsqlalchemy.sql functionssqlalchemy.sql operatorssqlalchemy.sql schemasqlalchemy.sql selectsqlalchemy.sql sqltypessqlalchemy.sql tablesqlalchemy.sql.compiler SQLCompilersqlalchemy.sql.elements ColumnElementsqlalchemy.sql.elements Labelsqlalchemy.sql.expression ClauseElementsqlalchemy.sql.expression ColumnClausesqlalchemy.sql.expression ColumnElementsqlalchemy.sql.expression Executablesqlalchemy.sql.expression FunctionElementsqlalchemy.sql.expression UnaryExpressionsqlalchemy.sql.functions FunctionElementsqlalchemy.sql.functions GenericFunctionsqlalchemy.sql.naming convsqlalchemy.sql.schema Columnsqlalchemy.sql.schema SchemaItemsqlalchemy.sql.sqltypes NullTypesqlalchemy.sql.util ClauseAdaptersqlalchemy.sql.visitors traversesqlalchemy.types Booleansqlalchemy.types Datesqlalchemy.types DateTimesqlalchemy.types Enumsqlalchemy.types Floatsqlalchemy.types Integersqlalchemy.types Intervalsqlalchemy.types NULLTYPEsqlalchemy.types Stringsqlalchemy.types Textsqlalchemy.types Timesqlalchemy.types TypeEnginesqlalchemy.types UserDefinedTypesqlalchemy.types to_instancesqlalchemy.util OrderedDictsqlalchemy.util OrderedSetsqlalchemy.util set_creation_ordersqlalchemy.util symbolsqlalchemy.util topologicalsqlalchemy.util.langhelpers public_factorysqlalchemy.util.langhelpers symbol ...or view the full table of contents.

Full Stack Python

Full Stack Python is an open book that explains concepts in plain language and provides helpful resources for those topics.
Updates via Twitter & Facebook.

Matt Makai 2012-2020