See also
│ │ │ │RowProxy is no longer a “proxy”; is now called Row and behaves like an enhanced named tuple
│ │ │ │References: #4710
│ │ │ │ │ │ │ │ │ │ │ │ -[engine] [change] [performance] [py3k] ¶
Disabled the “unicode returns” check that runs on dialect startup when │ │ │ │ +
[engine] [performance] ¶
The pool “pre-ping” feature has been refined to not invoke for a DBAPI │ │ │ │ +connection that was just opened in the same checkout operation. pre ping │ │ │ │ +only applies to a DBAPI connection that’s been checked into the pool │ │ │ │ +and is being checked out again.
│ │ │ │ +References: #4524
│ │ │ │ + │ │ │ │ +[engine] [performance] [change] [py3k] ¶
Disabled the “unicode returns” check that runs on dialect startup when │ │ │ │ running under Python 3, which for many years has occurred in order to test │ │ │ │ the current DBAPI’s behavior for whether or not it returns Python Unicode │ │ │ │ or Py2K strings for the VARCHAR and NVARCHAR datatypes. The check still │ │ │ │ occurs by default under Python 2, however the mechanism to test the │ │ │ │ behavior will be removed in SQLAlchemy 2.0 when Python 2 support is also │ │ │ │ removed.
│ │ │ │This logic was very effective when it was needed, however now that Python 3
│ │ │ │ @@ -8711,21 +8718,14 @@
│ │ │ │ dialect flags by setting the dialect level flag returns_unicode_strings
│ │ │ │ to one of String.RETURNS_CONDITIONAL or
│ │ │ │ String.RETURNS_BYTES, both of which will enable Unicode conversion
│ │ │ │ even under Python 3.
References: #5315
│ │ │ │ │ │ │ │[engine] [performance] ¶
The pool “pre-ping” feature has been refined to not invoke for a DBAPI │ │ │ │ -connection that was just opened in the same checkout operation. pre ping │ │ │ │ -only applies to a DBAPI connection that’s been checked into the pool │ │ │ │ -and is being checked out again.
│ │ │ │ -References: #4524
│ │ │ │ - │ │ │ │ -[engine] [bug] ¶
Revised the Connection.execution_options.schema_translate_map
│ │ │ │ feature such that the processing of the SQL statement to receive a specific
│ │ │ │ schema name occurs within the execution phase of the statement, rather than
│ │ │ │ at the compile phase. This is to support the statement being efficiently
│ │ │ │ cached. Previously, the current schema being rendered into the statement
│ │ │ │ for a particular run would be considered as part of the cache key itself,
│ │ │ │ meaning that for a run against hundreds of schemas, there would be hundreds
│ │ │ │ ├── html2text {}
│ │ │ │ │ @@ -6298,15 +6298,21 @@
│ │ │ │ │ returned by the ResultProxy is now the LegacyRow subclass, which maintains
│ │ │ │ │ mapping/tuple hybrid behavior, however the base Row class now behaves more
│ │ │ │ │ fully like a named tuple.
│ │ │ │ │ See also
│ │ │ │ │ RowProxy_is_no_longer_a_“proxy”;_is_now_called_Row_and_behaves_like_an_enhanced
│ │ │ │ │ named_tuple
│ │ │ │ │ References: #4710
│ │ │ │ │ -[engine] [change] [performance] [py3k] ¶
│ │ │ │ │ +[engine] [performance] ¶
│ │ │ │ │ +The pool “pre-ping” feature has been refined to not invoke for a DBAPI
│ │ │ │ │ +connection that was just opened in the same checkout operation. pre ping only
│ │ │ │ │ +applies to a DBAPI connection that’s been checked into the pool and is being
│ │ │ │ │ +checked out again.
│ │ │ │ │ +References: #4524
│ │ │ │ │ +[engine] [performance] [change] [py3k] ¶
│ │ │ │ │ Disabled the “unicode returns” check that runs on dialect startup when running
│ │ │ │ │ under Python 3, which for many years has occurred in order to test the current
│ │ │ │ │ DBAPI’s behavior for whether or not it returns Python Unicode or Py2K strings
│ │ │ │ │ for the VARCHAR and NVARCHAR datatypes. The check still occurs by default under
│ │ │ │ │ Python 2, however the mechanism to test the behavior will be removed in
│ │ │ │ │ SQLAlchemy 2.0 when Python 2 support is also removed.
│ │ │ │ │ This logic was very effective when it was needed, however now that Python 3 is
│ │ │ │ │ @@ -6314,20 +6320,14 @@
│ │ │ │ │ datatypes. In the unlikely case that a third party DBAPI does not support this,
│ │ │ │ │ the conversion logic within String is still available and the third party
│ │ │ │ │ dialect may specify this in its upfront dialect flags by setting the dialect
│ │ │ │ │ level flag returns_unicode_strings to one of String.RETURNS_CONDITIONAL or
│ │ │ │ │ String.RETURNS_BYTES, both of which will enable Unicode conversion even under
│ │ │ │ │ Python 3.
│ │ │ │ │ References: #5315
│ │ │ │ │ -[engine] [performance] ¶
│ │ │ │ │ -The pool “pre-ping” feature has been refined to not invoke for a DBAPI
│ │ │ │ │ -connection that was just opened in the same checkout operation. pre ping only
│ │ │ │ │ -applies to a DBAPI connection that’s been checked into the pool and is being
│ │ │ │ │ -checked out again.
│ │ │ │ │ -References: #4524
│ │ │ │ │ [engine] [bug] ¶
│ │ │ │ │ Revised the Connection.execution_options.schema_translate_map feature such that
│ │ │ │ │ the processing of the SQL statement to receive a specific schema name occurs
│ │ │ │ │ within the execution phase of the statement, rather than at the compile phase.
│ │ │ │ │ This is to support the statement being efficiently cached. Previously, the
│ │ │ │ │ current schema being rendered into the statement for a particular run would be
│ │ │ │ │ considered as part of the cache key itself, meaning that for a run against
│ │ │ ├── ./usr/share/doc/python-sqlalchemy-doc/html/orm/examples.html
│ │ │ │┄ Ordering differences only
│ │ │ │ @@ -313,38 +313,38 @@
│ │ │ │ where an intermediary class mediates the relationship between two
│ │ │ │ classes that are associated in a many-to-many pattern.
Listing of files:
basic_association.py - Illustrate a many-to-many relationship between an │ │ │ │ “Order” and a collection of “Item” objects, associating a purchase price │ │ │ │ with each via an association object called “OrderItem”
│ │ │ │proxied_association.py - Same example as basic_association, adding in
│ │ │ │ +usage of sqlalchemy.ext.associationproxy to make explicit references
│ │ │ │ +to OrderItem optional.
dict_of_sets_with_default.py - An advanced association proxy example which │ │ │ │ illustrates nesting of association proxies to produce multi-level Python │ │ │ │ collections, in this case a dictionary with string keys and sets of integers │ │ │ │ as values, which conceal the underlying mapped classes.
│ │ │ │proxied_association.py - Same example as basic_association, adding in
│ │ │ │ -usage of sqlalchemy.ext.associationproxy to make explicit references
│ │ │ │ -to OrderItem optional.
Examples illustrating the asyncio engine feature of SQLAlchemy.
│ │ │ │Listing of files:
async_orm.py - Illustrates use of the sqlalchemy.ext.asyncio.AsyncSession object │ │ │ │ -for asynchronous ORM use.
│ │ │ │ -greenlet_orm.py - Illustrates use of the sqlalchemy.ext.asyncio.AsyncSession object │ │ │ │ for asynchronous ORM use, including the optional run_sync() method.
│ │ │ │basic.py - Illustrates the asyncio engine / connection interface.
│ │ │ │async_orm.py - Illustrates use of the sqlalchemy.ext.asyncio.AsyncSession object │ │ │ │ +for asynchronous ORM use.
│ │ │ │ +gather_orm_statements.py - Illustrates how to run many statements concurrently using asyncio.gather()
│ │ │ │ along many asyncio database connections, merging ORM results into a single
│ │ │ │ AsyncSession.
HasAddresses mixin, which ensures that the
│ │ │ │ parent class is provided with an addresses collection
│ │ │ │ which contains Address objects.
│ │ │ │ The discriminator_on_association.py and generic_fk.py scripts │ │ │ │ are modernized versions of recipes presented in the 2007 blog post │ │ │ │ Polymorphic Associations with SQLAlchemy.
│ │ │ │Listing of files:
table_per_related.py - Illustrates a generic association which persists association │ │ │ │ -objects within individual tables, each one generated to persist │ │ │ │ -those objects on behalf of a particular parent class.
│ │ │ │ +table_per_association.py - Illustrates a mixin which provides a generic association │ │ │ │ +via a individually generated association tables for each parent class. │ │ │ │ +The associated objects themselves are persisted in a single table │ │ │ │ +shared among all parents.
│ │ │ │generic_fk.py - Illustrates a so-called “generic foreign key”, in a similar fashion │ │ │ │ to that of popular frameworks such as Django, ROR, etc. This │ │ │ │ approach bypasses standard referential integrity │ │ │ │ practices, in that the “foreign key” column is not actually │ │ │ │ constrained to refer to any particular table; instead, │ │ │ │ in-application logic is used to determine which table is referenced.
│ │ │ │table_per_association.py - Illustrates a mixin which provides a generic association │ │ │ │ -via a individually generated association tables for each parent class. │ │ │ │ -The associated objects themselves are persisted in a single table │ │ │ │ -shared among all parents.
│ │ │ │ -discriminator_on_association.py - Illustrates a mixin which provides a generic association │ │ │ │ using a single target table and a single association table, │ │ │ │ referred to by all parent tables. The association table │ │ │ │ contains a “discriminator” column which determines what type of │ │ │ │ parent object associates to each particular row in the association │ │ │ │ table.
│ │ │ │table_per_related.py - Illustrates a generic association which persists association │ │ │ │ +objects within individual tables, each one generated to persist │ │ │ │ +those objects on behalf of a particular parent class.
│ │ │ │ +Large collection example.
│ │ │ │Illustrates the options to use with │ │ │ │ @@ -501,33 +501,33 @@ │ │ │ │
See also
│ │ │ │ │ │ │ │Listing of files:
single_inserts.py - In this series of tests, we’re looking at a method that inserts a row │ │ │ │ +within a distinct transaction, and afterwards returns to essentially a │ │ │ │ +“closed” state. This would be analogous to an API call that starts up │ │ │ │ +a database connection, inserts the row, commits and closes.
│ │ │ │ +short_selects.py - This series of tests illustrates different ways to SELECT a single │ │ │ │ record by primary key
│ │ │ │__main__.py - Allows the examples/performance package to be run as a script.
│ │ │ │ +bulk_updates.py - This series of tests will illustrate different ways to UPDATE a large number │ │ │ │ +of rows in bulk (under construction! there’s just one test at the moment)
│ │ │ │large_resultsets.py - In this series of tests, we are looking at time to load a large number │ │ │ │ of very small and simple rows.
│ │ │ │single_inserts.py - In this series of tests, we’re looking at a method that inserts a row │ │ │ │ -within a distinct transaction, and afterwards returns to essentially a │ │ │ │ -“closed” state. This would be analogous to an API call that starts up │ │ │ │ -a database connection, inserts the row, commits and closes.
│ │ │ │ +__main__.py - Allows the examples/performance package to be run as a script.
│ │ │ │bulk_inserts.py - This series of tests illustrates different ways to INSERT a large number │ │ │ │ of rows in bulk.
│ │ │ │bulk_updates.py - This series of tests will illustrate different ways to UPDATE a large number │ │ │ │ -of rows in bulk (under construction! there’s just one test at the moment)
│ │ │ │ -This is the default form of run:
│ │ │ │$ python -m examples.performance single_inserts
│ │ │ │ @@ -669,22 +669,22 @@
│ │ │ │
│ │ │ │
│ │ │ │ Relationship Join Conditions¶
│ │ │ │ Examples of various relationship() configurations,
│ │ │ │ which make use of the primaryjoin argument to compose special types
│ │ │ │ of join conditions.
│ │ │ │ Listing of files:
│ │ │ │ -cast.py - Illustrate a relationship() that joins two columns where those
│ │ │ │ -columns are not of the same type, and a CAST must be used on the SQL
│ │ │ │ -side in order to match them.
│ │ │ │ -threeway.py - Illustrate a “three way join” - where a primary table joins to a remote
│ │ │ │ table via an association table, but then the primary table also needs
│ │ │ │ to refer to some columns in the remote table directly.
│ │ │ │ cast.py - Illustrate a relationship() that joins two columns where those
│ │ │ │ +columns are not of the same type, and a CAST must be used on the SQL
│ │ │ │ +side in order to match them.
│ │ │ │ +
│ │ │ │
│ │ │ │
│ │ │ │
│ │ │ │ Space Invaders¶
│ │ │ │ A Space Invaders game using SQLite as the state machine.
│ │ │ │ Originally developed in 2012. Adapted to work in Python 3.
│ │ │ │ @@ -814,47 +814,47 @@
│ │ │ │ assert type(other) is SomeClass and other.id == self.id Above, if two instance of SomeClass with the same version identifier
│ │ │ │ are updated and sent to the database for UPDATE concurrently, if the database
│ │ │ │ isolation level allows the two UPDATE statements to proceed, one will fail
│ │ │ │ because it no longer is against the last known version identifier.
Listing of files:
history_meta.py - Versioned mixin class and other utilities.
│ │ │ │ -test_versioning.py - Unit tests illustrating usage of the history_meta.py
│ │ │ │ module functions.
history_meta.py - Versioned mixin class and other utilities.
│ │ │ │ +Several examples that illustrate the technique of intercepting changes │ │ │ │ that would be first interpreted as an UPDATE on a row, and instead turning │ │ │ │ it into an INSERT of a new row, leaving the previous row intact as │ │ │ │ a historical version.
│ │ │ │Compare to the Versioning with a History Table example which writes a │ │ │ │ history row to a separate history table.
│ │ │ │Listing of files:
versioned_rows_w_versionid.py - Illustrates a method to intercept changes on objects, turning │ │ │ │ -an UPDATE statement on a single row into an INSERT statement, so that a new │ │ │ │ -row is inserted with the new data, keeping the old row intact.
│ │ │ │ -versioned_update_old_row.py - Illustrates the same UPDATE into INSERT technique of versioned_rows.py,
│ │ │ │ but also emits an UPDATE on the old row to affect a change in timestamp.
│ │ │ │ Also includes a SessionEvents.do_orm_execute() hook to limit queries
│ │ │ │ to only the most recent version.
versioned_map.py - A variant of the versioned_rows example built around the │ │ │ │ +concept of a “vertical table” structure, like those illustrated in │ │ │ │ +Vertical Attribute Mapping examples.
│ │ │ │ +versioned_rows.py - Illustrates a method to intercept changes on objects, turning │ │ │ │ an UPDATE statement on a single row into an INSERT statement, so that a new │ │ │ │ row is inserted with the new data, keeping the old row intact.
│ │ │ │versioned_map.py - A variant of the versioned_rows example built around the │ │ │ │ -concept of a “vertical table” structure, like those illustrated in │ │ │ │ -Vertical Attribute Mapping examples.
│ │ │ │ +versioned_rows_w_versionid.py - Illustrates a method to intercept changes on objects, turning │ │ │ │ +an UPDATE statement on a single row into an INSERT statement, so that a new │ │ │ │ +row is inserted with the new data, keeping the old row intact.
│ │ │ │Working examples of single-table, joined-table, and concrete-table │ │ │ │ inheritance as described in Mapping Class Inheritance Hierarchies.
│ │ │ │Listing of files:
single.py - Single-table (table-per-hierarchy) inheritance example.
│ │ │ │ +concrete.py - Concrete-table (table-per-class) inheritance example.
│ │ │ │joined.py - Joined-table (table-per-subclass) inheritance example.
│ │ │ │concrete.py - Concrete-table (table-per-class) inheritance example.
│ │ │ │ +single.py - Single-table (table-per-hierarchy) inheritance example.
│ │ │ │Examples illustrating modifications to SQLAlchemy’s attribute management │ │ │ │ system.
│ │ │ │Listing of files:
custom_management.py - Illustrates customized class instrumentation, using
│ │ │ │ -the sqlalchemy.ext.instrumentation extension package.
listen_for_events.py - Illustrates how to attach events to all instrumented attributes │ │ │ │ and listen for change events.
│ │ │ │active_column_defaults.py - Illustrates use of the AttributeEvents.init_scalar()
│ │ │ │ event, in conjunction with Core column defaults to provide
│ │ │ │ ORM objects that automatically produce the default value
│ │ │ │ when an un-set attribute is accessed.
custom_management.py - Illustrates customized class instrumentation, using
│ │ │ │ +the sqlalchemy.ext.instrumentation extension package.
A basic example of using the SQLAlchemy Sharding API. │ │ │ │ Sharding refers to horizontally scaling data across multiple │ │ │ │ @@ -961,20 +961,20 @@ │ │ │ │ more plain-spoken alternative, the “distinct entity” approach │ │ │ │ is a simple method of assigning objects to different tables (and potentially │ │ │ │ database nodes) in an explicit way - described on the wiki at │ │ │ │ EntityName.
│ │ │ │Listing of files:
separate_databases.py - Illustrates sharding using distinct SQLite databases.
│ │ │ │separate_schema_translates.py - Illustrates sharding using a single database with multiple schemas, │ │ │ │ -where a different “schema_translates_map” can be used for each shard.
│ │ │ │ -separate_tables.py - Illustrates sharding using a single SQLite database, that will however │ │ │ │ have multiple tables using a naming convention.
│ │ │ │separate_schema_translates.py - Illustrates sharding using a single database with multiple schemas, │ │ │ │ +where a different “schema_translates_map” can be used for each shard.
│ │ │ │ +Examples include demonstrations of the with_loader_criteria()
│ │ │ │ option as well as the SessionEvents.do_orm_execute() hook.
As of SQLAlchemy 1.4, the Query construct is unified
│ │ │ │ with the Select construct, so that these two objects
│ │ │ │ are mostly the same.
Listing of files:
filter_public.py - Illustrates a global criteria applied to entities of a particular type.
│ │ │ │ +temporal_range.py - Illustrates a custom per-query criteria that will be applied │ │ │ │ to selected entities.
│ │ │ │filter_public.py - Illustrates a global criteria applied to entities of a particular type.
│ │ │ │ -Illustrates how to embed │ │ │ │ dogpile.cache │ │ │ │ ├── html2text {} │ │ │ │ │ @@ -126,30 +126,31 @@ │ │ │ │ │ Examples illustrating the usage of the “association object” pattern, where an │ │ │ │ │ intermediary class mediates the relationship between two classes that are │ │ │ │ │ associated in a many-to-many pattern. │ │ │ │ │ Listing of files: │ │ │ │ │ * basic_association.py - Illustrate a many-to-many relationship between an │ │ │ │ │ “Order” and a collection of “Item” objects, associating a purchase price │ │ │ │ │ with each via an association object called “OrderItem” │ │ │ │ │ +proxied_association.py - Same example as basic_association, adding in usage of │ │ │ │ │ +sqlalchemy.ext.associationproxy to make explicit references to OrderItem │ │ │ │ │ +optional. │ │ │ │ │ dict_of_sets_with_default.py - An advanced association proxy example which │ │ │ │ │ illustrates nesting of association proxies to produce multi-level Python │ │ │ │ │ collections, in this case a dictionary with string keys and sets of integers as │ │ │ │ │ values, which conceal the underlying mapped classes. │ │ │ │ │ -proxied_association.py - Same example as basic_association, adding in usage of │ │ │ │ │ -sqlalchemy.ext.associationproxy to make explicit references to OrderItem │ │ │ │ │ -optional. │ │ │ │ │ │ │ │ │ │ **** Asyncio Integration¶ **** │ │ │ │ │ Examples illustrating the asyncio engine feature of SQLAlchemy. │ │ │ │ │ Listing of files: │ │ │ │ │ - * async_orm.py - Illustrates use of the sqlalchemy.ext.asyncio.AsyncSession │ │ │ │ │ - object for asynchronous ORM use. │ │ │ │ │ -greenlet_orm.py - Illustrates use of the sqlalchemy.ext.asyncio.AsyncSession │ │ │ │ │ -object for asynchronous ORM use, including the optional run_sync() method. │ │ │ │ │ + * greenlet_orm.py - Illustrates use of the │ │ │ │ │ + sqlalchemy.ext.asyncio.AsyncSession object for asynchronous ORM use, │ │ │ │ │ + including the optional run_sync() method. │ │ │ │ │ basic.py - Illustrates the asyncio engine / connection interface. │ │ │ │ │ +async_orm.py - Illustrates use of the sqlalchemy.ext.asyncio.AsyncSession │ │ │ │ │ +object for asynchronous ORM use. │ │ │ │ │ gather_orm_statements.py - Illustrates how to run many statements concurrently │ │ │ │ │ using asyncio.gather() along many asyncio database connections, merging ORM │ │ │ │ │ results into a single AsyncSession. │ │ │ │ │ │ │ │ │ │ **** Directed Graphs¶ **** │ │ │ │ │ An example of persistence for a directed graph structure. The graph is stored │ │ │ │ │ as a collection of edges, each referencing both a “lower” and an “upper” node │ │ │ │ │ @@ -177,31 +178,31 @@ │ │ │ │ │ Supplier, both subclassing the HasAddresses mixin, which ensures that the │ │ │ │ │ parent class is provided with an addresses collection which contains Address │ │ │ │ │ objects. │ │ │ │ │ The discriminator_on_association.py and generic_fk.py scripts are modernized │ │ │ │ │ versions of recipes presented in the 2007 blog post Polymorphic_Associations │ │ │ │ │ with_SQLAlchemy. │ │ │ │ │ Listing of files: │ │ │ │ │ - * table_per_related.py - Illustrates a generic association which persists │ │ │ │ │ - association objects within individual tables, each one generated to │ │ │ │ │ - persist those objects on behalf of a particular parent class. │ │ │ │ │ + * table_per_association.py - Illustrates a mixin which provides a generic │ │ │ │ │ + association via a individually generated association tables for each │ │ │ │ │ + parent class. The associated objects themselves are persisted in a single │ │ │ │ │ + table shared among all parents. │ │ │ │ │ generic_fk.py - Illustrates a so-called “generic foreign key”, in a similar │ │ │ │ │ fashion to that of popular frameworks such as Django, ROR, etc. This approach │ │ │ │ │ bypasses standard referential integrity practices, in that the “foreign key” │ │ │ │ │ column is not actually constrained to refer to any particular table; instead, │ │ │ │ │ in-application logic is used to determine which table is referenced. │ │ │ │ │ -table_per_association.py - Illustrates a mixin which provides a generic │ │ │ │ │ -association via a individually generated association tables for each parent │ │ │ │ │ -class. The associated objects themselves are persisted in a single table shared │ │ │ │ │ -among all parents. │ │ │ │ │ discriminator_on_association.py - Illustrates a mixin which provides a generic │ │ │ │ │ association using a single target table and a single association table, │ │ │ │ │ referred to by all parent tables. The association table contains a │ │ │ │ │ “discriminator” column which determines what type of parent object associates │ │ │ │ │ to each particular row in the association table. │ │ │ │ │ +table_per_related.py - Illustrates a generic association which persists │ │ │ │ │ +association objects within individual tables, each one generated to persist │ │ │ │ │ +those objects on behalf of a particular parent class. │ │ │ │ │ │ │ │ │ │ **** Large Collections¶ **** │ │ │ │ │ Large collection example. │ │ │ │ │ Illustrates the options to use with relationship() when the list of related │ │ │ │ │ objects is very large, including: │ │ │ │ │ * “dynamic” relationships which query slices of data as accessed │ │ │ │ │ * how to use ON DELETE CASCADE in conjunction with passive_deletes=True to │ │ │ │ │ @@ -262,28 +263,29 @@ │ │ │ │ │ $ python -m examples.performance bulk_inserts \ │ │ │ │ │ --dburl mysql+mysqldb://scott:tiger@localhost/test \ │ │ │ │ │ --profile --num 1000 │ │ │ │ │ See also │ │ │ │ │ How_can_I_profile_a_SQLAlchemy_powered_application? │ │ │ │ │ *** File Listing¶ *** │ │ │ │ │ Listing of files: │ │ │ │ │ - * short_selects.py - This series of tests illustrates different ways to │ │ │ │ │ - SELECT a single record by primary key │ │ │ │ │ -__main__.py - Allows the examples/performance package to be run as a script. │ │ │ │ │ + * single_inserts.py - In this series of tests, we’re looking at a method │ │ │ │ │ + that inserts a row within a distinct transaction, and afterwards returns │ │ │ │ │ + to essentially a “closed” state. This would be analogous to an API call │ │ │ │ │ + that starts up a database connection, inserts the row, commits and │ │ │ │ │ + closes. │ │ │ │ │ +short_selects.py - This series of tests illustrates different ways to SELECT a │ │ │ │ │ +single record by primary key │ │ │ │ │ +bulk_updates.py - This series of tests will illustrate different ways to UPDATE │ │ │ │ │ +a large number of rows in bulk (under construction! there’s just one test at │ │ │ │ │ +the moment) │ │ │ │ │ large_resultsets.py - In this series of tests, we are looking at time to load a │ │ │ │ │ large number of very small and simple rows. │ │ │ │ │ -single_inserts.py - In this series of tests, we’re looking at a method that │ │ │ │ │ -inserts a row within a distinct transaction, and afterwards returns to │ │ │ │ │ -essentially a “closed” state. This would be analogous to an API call that │ │ │ │ │ -starts up a database connection, inserts the row, commits and closes. │ │ │ │ │ +__main__.py - Allows the examples/performance package to be run as a script. │ │ │ │ │ bulk_inserts.py - This series of tests illustrates different ways to INSERT a │ │ │ │ │ large number of rows in bulk. │ │ │ │ │ -bulk_updates.py - This series of tests will illustrate different ways to UPDATE │ │ │ │ │ -a large number of rows in bulk (under construction! there’s just one test at │ │ │ │ │ -the moment) │ │ │ │ │ │ │ │ │ │ *** Running all tests with time¶ *** │ │ │ │ │ This is the default form of run: │ │ │ │ │ $ python -m examples.performance single_inserts │ │ │ │ │ Tests to run: test_orm_commit, test_bulk_save, │ │ │ │ │ test_bulk_insert_dictionaries, test_core, │ │ │ │ │ test_core_query_caching, test_dbapi_raw_w_connect, │ │ │ │ │ @@ -424,20 +426,20 @@ │ │ │ │ │ test_subqueryload : load everything, subquery eager loading. (1000 iterations); │ │ │ │ │ total time 2.977696 sec │ │ │ │ │ │ │ │ │ │ **** Relationship Join Conditions¶ **** │ │ │ │ │ Examples of various relationship() configurations, which make use of the │ │ │ │ │ primaryjoin argument to compose special types of join conditions. │ │ │ │ │ Listing of files: │ │ │ │ │ - * cast.py - Illustrate a relationship() that joins two columns where those │ │ │ │ │ - columns are not of the same type, and a CAST must be used on the SQL side │ │ │ │ │ - in order to match them. │ │ │ │ │ -threeway.py - Illustrate a “three way join” - where a primary table joins to a │ │ │ │ │ -remote table via an association table, but then the primary table also needs to │ │ │ │ │ -refer to some columns in the remote table directly. │ │ │ │ │ + * threeway.py - Illustrate a “three way join” - where a primary table joins │ │ │ │ │ + to a remote table via an association table, but then the primary table │ │ │ │ │ + also needs to refer to some columns in the remote table directly. │ │ │ │ │ +cast.py - Illustrate a relationship() that joins two columns where those │ │ │ │ │ +columns are not of the same type, and a CAST must be used on the SQL side in │ │ │ │ │ +order to match them. │ │ │ │ │ │ │ │ │ │ **** Space Invaders¶ **** │ │ │ │ │ A Space Invaders game using SQLite as the state machine. │ │ │ │ │ Originally developed in 2012. Adapted to work in Python 3. │ │ │ │ │ Runs in a textual console using ASCII art. │ │ │ │ │ [orm/space_invaders.jpg] │ │ │ │ │ To run: │ │ │ │ │ @@ -543,40 +545,40 @@ │ │ │ │ │ def __eq__(self, other): │ │ │ │ │ assert type(other) is SomeClass and other.id == self.id │ │ │ │ │ Above, if two instance of SomeClass with the same version identifier are │ │ │ │ │ updated and sent to the database for UPDATE concurrently, if the database │ │ │ │ │ isolation level allows the two UPDATE statements to proceed, one will fail │ │ │ │ │ because it no longer is against the last known version identifier. │ │ │ │ │ Listing of files: │ │ │ │ │ - * history_meta.py - Versioned mixin class and other utilities. │ │ │ │ │ -test_versioning.py - Unit tests illustrating usage of the history_meta.py │ │ │ │ │ -module functions. │ │ │ │ │ + * test_versioning.py - Unit tests illustrating usage of the history_meta.py │ │ │ │ │ + module functions. │ │ │ │ │ +history_meta.py - Versioned mixin class and other utilities. │ │ │ │ │ │ │ │ │ │ *** Versioning using Temporal Rows¶ *** │ │ │ │ │ Several examples that illustrate the technique of intercepting changes that │ │ │ │ │ would be first interpreted as an UPDATE on a row, and instead turning it into │ │ │ │ │ an INSERT of a new row, leaving the previous row intact as a historical │ │ │ │ │ version. │ │ │ │ │ Compare to the Versioning_with_a_History_Table example which writes a history │ │ │ │ │ row to a separate history table. │ │ │ │ │ Listing of files: │ │ │ │ │ - * versioned_rows_w_versionid.py - Illustrates a method to intercept changes │ │ │ │ │ - on objects, turning an UPDATE statement on a single row into an INSERT │ │ │ │ │ - statement, so that a new row is inserted with the new data, keeping the │ │ │ │ │ - old row intact. │ │ │ │ │ -versioned_update_old_row.py - Illustrates the same UPDATE into INSERT technique │ │ │ │ │ -of versioned_rows.py, but also emits an UPDATE on the old row to affect a │ │ │ │ │ -change in timestamp. Also includes a SessionEvents.do_orm_execute() hook to │ │ │ │ │ -limit queries to only the most recent version. │ │ │ │ │ -versioned_rows.py - Illustrates a method to intercept changes on objects, │ │ │ │ │ -turning an UPDATE statement on a single row into an INSERT statement, so that a │ │ │ │ │ -new row is inserted with the new data, keeping the old row intact. │ │ │ │ │ + * versioned_update_old_row.py - Illustrates the same UPDATE into INSERT │ │ │ │ │ + technique of versioned_rows.py, but also emits an UPDATE on the old row │ │ │ │ │ + to affect a change in timestamp. Also includes a │ │ │ │ │ + SessionEvents.do_orm_execute() hook to limit queries to only the most │ │ │ │ │ + recent version. │ │ │ │ │ versioned_map.py - A variant of the versioned_rows example built around the │ │ │ │ │ concept of a “vertical table” structure, like those illustrated in Vertical │ │ │ │ │ Attribute_Mapping examples. │ │ │ │ │ +versioned_rows.py - Illustrates a method to intercept changes on objects, │ │ │ │ │ +turning an UPDATE statement on a single row into an INSERT statement, so that a │ │ │ │ │ +new row is inserted with the new data, keeping the old row intact. │ │ │ │ │ +versioned_rows_w_versionid.py - Illustrates a method to intercept changes on │ │ │ │ │ +objects, turning an UPDATE statement on a single row into an INSERT statement, │ │ │ │ │ +so that a new row is inserted with the new data, keeping the old row intact. │ │ │ │ │ │ │ │ │ │ **** Vertical Attribute Mapping¶ **** │ │ │ │ │ Illustrates “vertical table” mappings. │ │ │ │ │ A “vertical table” refers to a technique where individual attributes of an │ │ │ │ │ object are stored as distinct rows in a table. The “vertical table” technique │ │ │ │ │ is used to persist objects which can have a varied set of attributes, at the │ │ │ │ │ expense of simple query control and brevity. It is commonly found in content/ │ │ │ │ │ @@ -605,30 +607,30 @@ │ │ │ │ │ dictionary. │ │ │ │ │ │ │ │ │ │ ***** Inheritance Mapping Recipes¶ ***** │ │ │ │ │ **** Basic Inheritance Mappings¶ **** │ │ │ │ │ Working examples of single-table, joined-table, and concrete-table inheritance │ │ │ │ │ as described in Mapping_Class_Inheritance_Hierarchies. │ │ │ │ │ Listing of files: │ │ │ │ │ - * single.py - Single-table (table-per-hierarchy) inheritance example. │ │ │ │ │ + * concrete.py - Concrete-table (table-per-class) inheritance example. │ │ │ │ │ joined.py - Joined-table (table-per-subclass) inheritance example. │ │ │ │ │ -concrete.py - Concrete-table (table-per-class) inheritance example. │ │ │ │ │ +single.py - Single-table (table-per-hierarchy) inheritance example. │ │ │ │ │ │ │ │ │ │ ***** Special APIs¶ ***** │ │ │ │ │ **** Attribute Instrumentation¶ **** │ │ │ │ │ Examples illustrating modifications to SQLAlchemy’s attribute management │ │ │ │ │ system. │ │ │ │ │ Listing of files: │ │ │ │ │ - * custom_management.py - Illustrates customized class instrumentation, │ │ │ │ │ - using the sqlalchemy.ext.instrumentation extension package. │ │ │ │ │ -listen_for_events.py - Illustrates how to attach events to all instrumented │ │ │ │ │ -attributes and listen for change events. │ │ │ │ │ + * listen_for_events.py - Illustrates how to attach events to all │ │ │ │ │ + instrumented attributes and listen for change events. │ │ │ │ │ active_column_defaults.py - Illustrates use of the AttributeEvents.init_scalar │ │ │ │ │ () event, in conjunction with Core column defaults to provide ORM objects that │ │ │ │ │ automatically produce the default value when an un-set attribute is accessed. │ │ │ │ │ +custom_management.py - Illustrates customized class instrumentation, using the │ │ │ │ │ +sqlalchemy.ext.instrumentation extension package. │ │ │ │ │ │ │ │ │ │ **** Horizontal Sharding¶ **** │ │ │ │ │ A basic example of using the SQLAlchemy Sharding API. Sharding refers to │ │ │ │ │ horizontally scaling data across multiple databases. │ │ │ │ │ The basic components of a “sharded” mapping are: │ │ │ │ │ * multiple Engine instances, each assigned a “shard id”. These Engine │ │ │ │ │ instances may refer to different databases, or different schemas / │ │ │ │ │ @@ -652,34 +654,34 @@ │ │ │ │ │ issue of organizing instances among multiple databases. For a more plain-spoken │ │ │ │ │ alternative, the “distinct entity” approach is a simple method of assigning │ │ │ │ │ objects to different tables (and potentially database nodes) in an explicit way │ │ │ │ │ - described on the wiki at EntityName. │ │ │ │ │ Listing of files: │ │ │ │ │ * separate_databases.py - Illustrates sharding using distinct SQLite │ │ │ │ │ databases. │ │ │ │ │ +separate_tables.py - Illustrates sharding using a single SQLite database, that │ │ │ │ │ +will however have multiple tables using a naming convention. │ │ │ │ │ separate_schema_translates.py - Illustrates sharding using a single database │ │ │ │ │ with multiple schemas, where a different “schema_translates_map” can be used │ │ │ │ │ for each shard. │ │ │ │ │ -separate_tables.py - Illustrates sharding using a single SQLite database, that │ │ │ │ │ -will however have multiple tables using a naming convention. │ │ │ │ │ │ │ │ │ │ ***** Extending the ORM¶ ***** │ │ │ │ │ **** ORM Query Events¶ **** │ │ │ │ │ Recipes which illustrate augmentation of ORM SELECT behavior as used by │ │ │ │ │ Session.execute() with 2.0_style use of select(), as well as the 1.x_style │ │ │ │ │ Query object. │ │ │ │ │ Examples include demonstrations of the with_loader_criteria() option as well as │ │ │ │ │ the SessionEvents.do_orm_execute() hook. │ │ │ │ │ As of SQLAlchemy 1.4, the Query construct is unified with the Select construct, │ │ │ │ │ so that these two objects are mostly the same. │ │ │ │ │ Listing of files: │ │ │ │ │ - * temporal_range.py - Illustrates a custom per-query criteria that will be │ │ │ │ │ - applied to selected entities. │ │ │ │ │ -filter_public.py - Illustrates a global criteria applied to entities of a │ │ │ │ │ -particular type. │ │ │ │ │ + * filter_public.py - Illustrates a global criteria applied to entities of a │ │ │ │ │ + particular type. │ │ │ │ │ +temporal_range.py - Illustrates a custom per-query criteria that will be │ │ │ │ │ +applied to selected entities. │ │ │ │ │ │ │ │ │ │ **** Dogpile Caching¶ **** │ │ │ │ │ Illustrates how to embed dogpile.cache functionality with ORM queries, allowing │ │ │ │ │ full cache control as well as the ability to pull “lazy loaded” attributes from │ │ │ │ │ long term cache. │ │ │ │ │ In this demo, the following techniques are illustrated: │ │ │ │ │ * Using the SessionEvents.do_orm_execute() event hook │ │ │ ├── ./usr/share/doc/python-sqlalchemy-doc/html/searchindex.js │ │ │ │ ├── js-beautify {} │ │ │ │ │ @@ -8497,20 +8497,20 @@ │ │ │ │ │ "3414": [13, 25], │ │ │ │ │ "alchemy2": 13, │ │ │ │ │ "4644": 13, │ │ │ │ │ "5649": 13, │ │ │ │ │ "get_sequence_nam": [13, 48, 52], │ │ │ │ │ "2056": 13, │ │ │ │ │ "4755": 13, │ │ │ │ │ + "4524": 13, │ │ │ │ │ "upfront": 13, │ │ │ │ │ "returns_unicode_str": [13, 48], │ │ │ │ │ "returns_condit": [13, 59], │ │ │ │ │ "returns_byt": [13, 59], │ │ │ │ │ "5315": 13, │ │ │ │ │ - "4524": 13, │ │ │ │ │ "hundr": [13, 21, 24, 25, 31, 76, 136, 137, 155], │ │ │ │ │ "4645": [13, 25], │ │ │ │ │ "4808": [13, 25], │ │ │ │ │ "5004": [13, 25], │ │ │ │ │ "har": [13, 25], │ │ │ │ │ "4712": 13, │ │ │ │ │ "5526": [13, 25], │ │ │ │ │ @@ -12439,17 +12439,17 @@ │ │ │ │ │ "n5": 98, │ │ │ │ │ "add_neighbor": 98, │ │ │ │ │ "higher_neighbor": 98, │ │ │ │ │ "directed_graph": 98, │ │ │ │ │ "supplier": 98, │ │ │ │ │ "hasaddress": 98, │ │ │ │ │ "generic_fk": 98, │ │ │ │ │ - "table_per_rel": 98, │ │ │ │ │ - "ror": 98, │ │ │ │ │ "table_per_associ": 98, │ │ │ │ │ + "ror": 98, │ │ │ │ │ + "table_per_rel": 98, │ │ │ │ │ "materialized_path": 98, │ │ │ │ │ "nested_set": 98, │ │ │ │ │ "single_insert": 98, │ │ │ │ │ "bulk_upd": 98, │ │ │ │ │ "test_orm_commit": 98, │ │ │ │ │ "test_bulk_insert_dictionari": 98, │ │ │ │ │ "test_cor": 98, │ │ │ │ │ @@ -12504,34 +12504,34 @@ │ │ │ │ │ "sc1": 98, │ │ │ │ │ "sc1modifi": 98, │ │ │ │ │ "someclasshistori": 98, │ │ │ │ │ "__history_mapper__": 98, │ │ │ │ │ "_history_mapp": 98, │ │ │ │ │ "somehistoryclass": 98, │ │ │ │ │ "use_mapper_vers": 98, │ │ │ │ │ - "versioned_rows_w_versionid": 98, │ │ │ │ │ "versioned_update_old_row": 98, │ │ │ │ │ "versioned_map": 98, │ │ │ │ │ + "versioned_rows_w_versionid": 98, │ │ │ │ │ "breviti": 98, │ │ │ │ │ "shrew": 98, │ │ │ │ │ "anim": 98, │ │ │ │ │ "cute": 98, │ │ │ │ │ "weasel": 98, │ │ │ │ │ "poison": 98, │ │ │ │ │ "animalfact": 98, │ │ │ │ │ "custom_manag": 98, │ │ │ │ │ "weather": 98, │ │ │ │ │ "contin": 98, │ │ │ │ │ "spoken": 98, │ │ │ │ │ "separate_databas": 98, │ │ │ │ │ + "separate_t": 98, │ │ │ │ │ "separate_schema_transl": 98, │ │ │ │ │ "schema_translates_map": 98, │ │ │ │ │ - "separate_t": 98, │ │ │ │ │ - "temporal_rang": 98, │ │ │ │ │ "filter_publ": 98, │ │ │ │ │ + "temporal_rang": 98, │ │ │ │ │ "demo": 98, │ │ │ │ │ "datafil": 98, │ │ │ │ │ "helloworld": 98, │ │ │ │ │ "local_session_cach": 98, │ │ │ │ │ "datamodel": 98, │ │ │ │ │ "postalcod": 98, │ │ │ │ │ "citi": [98, 124, 133],