Examples illustrating the usage of the \u201cassociation object\u201d pattern,\n where an intermediary class mediates the relationship between two\n classes that are associated in a many-to-many pattern.
\nListing of files:
basic_association.py - Illustrate a many-to-many relationship between an\n+\u201cOrder\u201d and a collection of \u201cItem\u201d objects, associating a purchase price\n+with each via an association object called \u201cOrderItem\u201d
\n+dict_of_sets_with_default.py - An advanced association proxy example which\n illustrates nesting of association proxies to produce multi-level Python\n collections, in this case a dictionary with string keys and sets of integers\n as values, which conceal the underlying mapped classes.
\nbasic_association.py - Illustrate a many-to-many relationship between an\n-\u201cOrder\u201d and a collection of \u201cItem\u201d objects, associating a purchase price\n-with each via an association object called \u201cOrderItem\u201d
\n-proxied_association.py - Same example as basic_association, adding in\n usage of sqlalchemy.ext.associationproxy to make explicit references\n to OrderItem optional.
discriminator_on_association.py - Illustrates a mixin which provides a generic association\n using a single target table and a single association table,\n referred to by all parent tables. The association table\n contains a \u201cdiscriminator\u201d column which determines what type of\n parent object associates to each particular row in the association\n table.
\ntable_per_association.py - Illustrates a mixin which provides a generic association\n-via a individually generated association tables for each parent class.\n-The associated objects themselves are persisted in a single table\n-shared among all parents.
\n+table_per_related.py - Illustrates a generic association which persists association\n+objects within individual tables, each one generated to persist\n+those objects on behalf of a particular parent class.
\ngeneric_fk.py - Illustrates a so-called \u201cgeneric foreign key\u201d, in a similar fashion\n to that of popular frameworks such as Django, ROR, etc. This\n approach bypasses standard referential integrity\n practices, in that the \u201cforeign key\u201d column is not actually\n constrained to refer to any particular table; instead,\n in-application logic is used to determine which table is referenced.
\ntable_per_related.py - Illustrates a generic association which persists association\n-objects within individual tables, each one generated to persist\n-those objects on behalf of a particular parent class.
\n+table_per_association.py - Illustrates a mixin which provides a generic association\n+via a individually generated association tables for each parent class.\n+The associated objects themselves are persisted in a single table\n+shared among all parents.
\nLarge collection example.
\n@@ -389,24 +389,24 @@\nSee also
\n \nListing of files:
__main__.py - Allows the examples/performance package to be run as a script.
\n-short_selects.py - This series of tests illustrates different ways to SELECT a single\n-record by primary key
\n-single_inserts.py - In this series of tests, we\u2019re looking at a method that inserts a row\n within a distinct transaction, and afterwards returns to essentially a\n \u201cclosed\u201d state. This would be analogous to an API call that starts up\n a database connection, inserts the row, commits and closes.
\nshort_selects.py - This series of tests illustrates different ways to SELECT a single\n+record by primary key
\n+__main__.py - Allows the examples/performance package to be run as a script.
\n+bulk_inserts.py - This series of tests illustrates different ways to INSERT a large number\n of rows in bulk.
\nlarge_resultsets.py - In this series of tests, we are looking at time to load a large number\n of very small and simple rows.
\nbulk_updates.py - This series of tests illustrates different ways to UPDATE a large number\n@@ -557,22 +557,22 @@\n
Examples of various relationship() configurations,\n which make use of the primaryjoin argument to compose special types\n of join conditions.
Listing of files:
cast.py - Illustrate a relationship() that joins two columns where those\n-columns are not of the same type, and a CAST must be used on the SQL\n-side in order to match them.
threeway.py - Illustrate a \u201cthree way join\u201d - where a primary table joins to a remote\n table via an association table, but then the primary table also needs\n to refer to some columns in the remote table directly.
\ncast.py - Illustrate a relationship() that joins two columns where those\n+columns are not of the same type, and a CAST must be used on the SQL\n+side in order to match them.
A Space Invaders game using SQLite as the state machine.
\nOriginally developed in 2012. Adapted to work in Python 3.
\n@@ -719,31 +719,31 @@\nSeveral examples that illustrate the technique of intercepting changes\n that would be first interpreted as an UPDATE on a row, and instead turning\n it into an INSERT of a new row, leaving the previous row intact as\n a historical version.
\nCompare to the Versioning with a History Table example which writes a\n history row to a separate history table.
\nListing of files:
versioned_rows.py - Illustrates a method to intercept changes on objects, turning\n+
versioned_update_old_row.py - Illustrates the same UPDATE into INSERT technique of versioned_rows.py,\n+but also emits an UPDATE on the old row to affect a change in timestamp.\n+Also includes a QueryEvents.before_compile() hook to limit queries\n+to only the most recent version.
versioned_rows_w_versionid.py - Illustrates a method to intercept changes on objects, turning\n an UPDATE statement on a single row into an INSERT statement, so that a new\n row is inserted with the new data, keeping the old row intact.
\nversioned_map.py - A variant of the versioned_rows example built around the\n concept of a \u201cvertical table\u201d structure, like those illustrated in\n Vertical Attribute Mapping examples.
\nversioned_rows_w_versionid.py - Illustrates a method to intercept changes on objects, turning\n+
versioned_rows.py - Illustrates a method to intercept changes on objects, turning\n an UPDATE statement on a single row into an INSERT statement, so that a new\n row is inserted with the new data, keeping the old row intact.
\nversioned_update_old_row.py - Illustrates the same UPDATE into INSERT technique of versioned_rows.py,\n-but also emits an UPDATE on the old row to affect a change in timestamp.\n-Also includes a QueryEvents.before_compile() hook to limit queries\n-to only the most recent version.
Illustrates \u201cvertical table\u201d mappings.
\n@@ -768,54 +768,54 @@\n q = (session.query(Animal).\n filter(Animal.facts.any(\n and_(AnimalFact.key == u'weasel-like',\n AnimalFact.value == True))))\n print('weasel-like animals', q.all())Listing of files:
dictlike-polymorphic.py - Mapping a polymorphic-valued vertical table as a dictionary.
\n-dictlike.py - Mapping a vertical table as a dictionary.
\ndictlike-polymorphic.py - Mapping a polymorphic-valued vertical table as a dictionary.
\n+Working examples of single-table, joined-table, and concrete-table\n inheritance as described in Mapping Class Inheritance Hierarchies.
\nListing of files:
concrete.py - Concrete-table (table-per-class) inheritance example.
\nsingle.py - Single-table (table-per-hierarchy) inheritance example.
\n-joined.py - Joined-table (table-per-subclass) inheritance example.
\nsingle.py - Single-table (table-per-hierarchy) inheritance example.
\n+Examples illustrating modifications to SQLAlchemy\u2019s attribute management\n system.
\nListing of files:
listen_for_events.py - Illustrates how to attach events to all instrumented attributes\n+and listen for change events.
\n+active_column_defaults.py - Illustrates use of the AttributeEvents.init_scalar()\n event, in conjunction with Core column defaults to provide\n ORM objects that automatically produce the default value\n when an un-set attribute is accessed.
listen_for_events.py - Illustrates how to attach events to all instrumented attributes\n-and listen for change events.
\n-custom_management.py - Illustrates customized class instrumentation, using\n the sqlalchemy.ext.instrumentation extension package.