diff options
author | Mike Bayer <mike_mp@zzzcomputing.com> | 2010-09-04 19:59:21 -0400 |
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committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2010-09-04 19:59:21 -0400 |
commit | b42cbed42765cd00962868c248cee4b1b448c948 (patch) | |
tree | 755f90b6aa04f8d7bb8c45f0b293272eec4bab7b /lib | |
parent | a315c5d431cf0598448a789d71aae7e2903dab32 (diff) | |
download | sqlalchemy-b42cbed42765cd00962868c248cee4b1b448c948.tar.gz |
almost through.
Diffstat (limited to 'lib')
-rw-r--r-- | lib/sqlalchemy/ext/compiler.py | 2 | ||||
-rw-r--r-- | lib/sqlalchemy/ext/sqlsoup.py | 10 | ||||
-rw-r--r-- | lib/sqlalchemy/orm/__init__.py | 3 | ||||
-rw-r--r-- | lib/sqlalchemy/orm/interfaces.py | 13 | ||||
-rw-r--r-- | lib/sqlalchemy/orm/query.py | 9 | ||||
-rw-r--r-- | lib/sqlalchemy/orm/session.py | 72 | ||||
-rw-r--r-- | lib/sqlalchemy/schema.py | 72 | ||||
-rw-r--r-- | lib/sqlalchemy/types.py | 12 |
8 files changed, 111 insertions, 82 deletions
diff --git a/lib/sqlalchemy/ext/compiler.py b/lib/sqlalchemy/ext/compiler.py index 12f1e443d..1bf4b1447 100644 --- a/lib/sqlalchemy/ext/compiler.py +++ b/lib/sqlalchemy/ext/compiler.py @@ -119,6 +119,8 @@ overriding routine and cause an endless loop. Such as, to add "prefix" to all The above compiler will prefix all INSERT statements with "some prefix" when compiled. +.. _type_compilation_extension: + Changing Compilation of Types ============================= diff --git a/lib/sqlalchemy/ext/sqlsoup.py b/lib/sqlalchemy/ext/sqlsoup.py index e54cde3ed..e8234e7c7 100644 --- a/lib/sqlalchemy/ext/sqlsoup.py +++ b/lib/sqlalchemy/ext/sqlsoup.py @@ -3,7 +3,15 @@ Introduction ============ SqlSoup provides a convenient way to access existing database tables without -having to declare table or mapper classes ahead of time. It is built on top of the SQLAlchemy ORM and provides a super-minimalistic interface to an existing database. +having to declare table or mapper classes ahead of time. It is built on top of +the SQLAlchemy ORM and provides a super-minimalistic interface to an existing +database. + +SqlSoup effectively provides a coarse grained, alternative interface to +working with the SQLAlchemy ORM, providing a "self configuring" interface +for extremely rudimental operations. It's somewhat akin to a +"super novice mode" version of the ORM. While SqlSoup can be very handy, +users are strongly encouraged to use the full ORM for non-trivial applications. Suppose we have a database with users, books, and loans tables (corresponding to the PyWebOff dataset, if you're curious). diff --git a/lib/sqlalchemy/orm/__init__.py b/lib/sqlalchemy/orm/__init__.py index 9200b52fd..e59c5863b 100644 --- a/lib/sqlalchemy/orm/__init__.py +++ b/lib/sqlalchemy/orm/__init__.py @@ -1150,6 +1150,9 @@ def contains_eager(*keys, **kwargs): See also :func:`eagerload` for the "automatic" version of this functionality. + For additional examples of :func:`contains_eager` see + :ref:`contains_eager`. + """ alias = kwargs.pop('alias', None) if kwargs: diff --git a/lib/sqlalchemy/orm/interfaces.py b/lib/sqlalchemy/orm/interfaces.py index b71ec4db5..0a65c8a44 100644 --- a/lib/sqlalchemy/orm/interfaces.py +++ b/lib/sqlalchemy/orm/interfaces.py @@ -51,7 +51,7 @@ MANYTOMANY = util.symbol('MANYTOMANY') class MapperExtension(object): """Base implementation for customizing ``Mapper`` behavior. - + New extension classes subclass ``MapperExtension`` and are specified using the ``extension`` mapper() argument, which is a single ``MapperExtension`` or a list of such. A single mapper @@ -74,8 +74,9 @@ class MapperExtension(object): when this symbol is returned. Like EXT_CONTINUE, it also has additional significance in some cases that a default mapper activity will not be performed. - + """ + def instrument_class(self, mapper, class_): """Receive a class when the mapper is first constructed, and has applied instrumentation to the mapped class. @@ -185,7 +186,7 @@ class MapperExtension(object): \**flags extra information about the row, same as criterion in ``create_row_processor()`` method of - :class:`~sqlalchemy.orm.interfaces.MapperProperty` + :class:`~sqlalchemy.orm.interfaces.MapperProperty` """ return EXT_CONTINUE @@ -324,10 +325,10 @@ class MapperExtension(object): def after_delete(self, mapper, connection, instance): """Receive an object instance after that instance is deleted. - - The return value is only significant within the ``MapperExtension`` + + The return value is only significant within the ``MapperExtension`` chain; the parent mapper's behavior isn't modified by this method. - + """ return EXT_CONTINUE diff --git a/lib/sqlalchemy/orm/query.py b/lib/sqlalchemy/orm/query.py index fdc426a07..41e9a4890 100644 --- a/lib/sqlalchemy/orm/query.py +++ b/lib/sqlalchemy/orm/query.py @@ -779,8 +779,13 @@ class Query(object): def options(self, *args): """Return a new Query object, applying the given list of - MapperOptions. - + mapper options. + + Most supplied options regard changing how column- and + relationship-mapped attributes are loaded. See the sections + :ref:`deferred` and :ref:`loading_toplevel` for reference + documentation. + """ return self._options(False, *args) diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py index 4727de218..d906df2a3 100644 --- a/lib/sqlalchemy/orm/session.py +++ b/lib/sqlalchemy/orm/session.py @@ -446,71 +446,8 @@ class SessionTransaction(object): class Session(object): """Manages persistence operations for ORM-mapped objects. - The Session is the front end to SQLAlchemy's **Unit of Work** - implementation. The concept behind Unit of Work is to track modifications - to a field of objects, and then be able to flush those changes to the - database in a single operation. - - SQLAlchemy's unit of work includes these functions: - - * The ability to track in-memory changes on scalar- and collection-based - object attributes, such that database persistence operations can be - assembled based on those changes. - - * The ability to organize individual SQL queries and population of newly - generated primary and foreign key-holding attributes during a persist - operation such that referential integrity is maintained at all times. - - * The ability to maintain insert ordering against the order in which new - instances were added to the session. - - * An Identity Map, which is a dictionary keying instances to their unique - primary key identity. This ensures that only one copy of a particular - entity is ever present within the session, even if repeated load - operations for the same entity occur. This allows many parts of an - application to get a handle to a particular object without any chance of - modifications going to two different places. - - When dealing with instances of mapped classes, an instance may be - *attached* to a particular Session, else it is *unattached* . An instance - also may or may not correspond to an actual row in the database. These - conditions break up into four distinct states: - - * *Transient* - an instance that's not in a session, and is not saved to - the database; i.e. it has no database identity. The only relationship - such an object has to the ORM is that its class has a ``mapper()`` - associated with it. - - * *Pending* - when you ``add()`` a transient instance, it becomes - pending. It still wasn't actually flushed to the database yet, but it - will be when the next flush occurs. - - * *Persistent* - An instance which is present in the session and has a - record in the database. You get persistent instances by either flushing - so that the pending instances become persistent, or by querying the - database for existing instances (or moving persistent instances from - other sessions into your local session). - - * *Detached* - an instance which has a record in the database, but is not - in any session. Theres nothing wrong with this, and you can use objects - normally when they're detached, **except** they will not be able to - issue any SQL in order to load collections or attributes which are not - yet loaded, or were marked as "expired". - - The session methods which control instance state include :meth:`.Session.add`, - :meth:`.Session.delete`, :meth:`.Session.merge`, and :meth:`.Session.expunge`. - - The Session object is generally **not** threadsafe. A session which is - set to ``autocommit`` and is only read from may be used by concurrent - threads if it's acceptable that some object instances may be loaded twice. - - The typical pattern to managing Sessions in a multi-threaded environment - is either to use mutexes to limit concurrent access to one thread at a - time, or more commonly to establish a unique session for every thread, - using a threadlocal variable. SQLAlchemy provides a thread-managed - Session adapter, provided by the :func:`~sqlalchemy.orm.scoped_session` - function. - + The Session's usage paradigm is described at :ref:`session_toplevel`. + """ public_methods = ( @@ -529,8 +466,9 @@ class Session(object): query_cls=query.Query): """Construct a new Session. - Arguments to ``Session`` are described using the - :func:`~sqlalchemy.orm.sessionmaker` function. + Arguments to :class:`.Session` are described using the + :func:`.sessionmaker` function, which is the + typical point of entry. """ diff --git a/lib/sqlalchemy/schema.py b/lib/sqlalchemy/schema.py index 5b5983858..b01d815a9 100644 --- a/lib/sqlalchemy/schema.py +++ b/lib/sqlalchemy/schema.py @@ -450,8 +450,22 @@ class Table(SchemaItem, expression.TableClause): def tometadata(self, metadata, schema=RETAIN_SCHEMA): - """Return a copy of this ``Table`` associated with a different - ``MetaData``.""" + """Return a copy of this :class:`Table` associated with a different + :class:`MetaData`. + + E.g.:: + + # create two metadata + meta1 = MetaData('sqlite:///querytest.db') + meta2 = MetaData() + + # load 'users' from the sqlite engine + users_table = Table('users', meta1, autoload=True) + + # create the same Table object for the plain metadata + users_table_2 = users_table.tometadata(meta2) + + """ try: if schema is RETAIN_SCHEMA: @@ -1243,7 +1257,23 @@ class DefaultGenerator(SchemaItem): class ColumnDefault(DefaultGenerator): """A plain default value on a column. - This could correspond to a constant, a callable function, or a SQL clause. + This could correspond to a constant, a callable function, + or a SQL clause. + + :class:`.ColumnDefault` is generated automatically + whenever the ``default``, ``onupdate`` arguments of + :class:`.Column` are used. A :class:`.ColumnDefault` + can be passed positionally as well. + + For example, the following:: + + Column('foo', Integer, default=50) + + Is equivalent to:: + + Column('foo', Integer, ColumnDefault(50)) + + """ def __init__(self, arg, **kwargs): @@ -1374,7 +1404,20 @@ class Sequence(DefaultGenerator): class FetchedValue(object): - """A default that takes effect on the database side.""" + """A marker for a transparent database-side default. + + Use :class:`.FetchedValue` when the database is configured + to provide some automatic default for a column. + + E.g.:: + + Column('foo', Integer, FetchedValue()) + + Would indicate that some trigger or default generator + will create a new value for the ``foo`` column during an + INSERT. + + """ def __init__(self, for_update=False): self.for_update = for_update @@ -1391,7 +1434,26 @@ class FetchedValue(object): class DefaultClause(FetchedValue): - """A DDL-specified DEFAULT column value.""" + """A DDL-specified DEFAULT column value. + + :class:`.DefaultClause` is a :class:`.FetchedValue` + that also generates a "DEFAULT" clause when + "CREATE TABLE" is emitted. + + :class:`.DefaultClause` is generated automatically + whenever the ``server_default``, ``server_onupdate`` arguments of + :class:`.Column` are used. A :class:`.DefaultClause` + can be passed positionally as well. + + For example, the following:: + + Column('foo', Integer, server_default="50") + + Is equivalent to:: + + Column('foo', Integer, DefaultClause("50")) + + """ def __init__(self, arg, for_update=False): util.assert_arg_type(arg, (basestring, diff --git a/lib/sqlalchemy/types.py b/lib/sqlalchemy/types.py index f00cc2e3c..a3769dcd6 100644 --- a/lib/sqlalchemy/types.py +++ b/lib/sqlalchemy/types.py @@ -485,6 +485,14 @@ class TypeDecorator(AbstractType): return self.impl.compare_values(x, y) def is_mutable(self): + """Return True if the target Python type is 'mutable'. + + When this method is overridden, :meth:`copy_value` should + also be supplied. The :class:`.MutableType` mixin + is recommended as a helper. + + """ + return self.impl.is_mutable() def _adapt_expression(self, op, othertype): @@ -562,7 +570,9 @@ class MutableType(object): """ def is_mutable(self): - """Return True, mutable.""" + """Return True if the target Python type is 'mutable'. + + """ return True def copy_value(self, value): |