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Updated SqlAlchemy

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This commit is contained in:
Christoffer Viken
2017-04-15 16:27:12 +00:00
parent 2c790e1fe1
commit e3267d4bda
59 changed files with 30236 additions and 26049 deletions
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392
sqlalchemy/engine/__init__.py
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@@ -1,5 +1,6 @@
# engine/__init__.py
# Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Michael Bayer mike_mp@zzzcomputing.com
# Copyright (C) 2005-2017 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
@@ -9,7 +10,7 @@
The engine package defines the basic components used to interface
DB-API modules with higher-level statement construction,
connection-management, execution and result contexts. The primary
"entry point" class into this package is the Engine and it's public
"entry point" class into this package is the Engine and its public
constructor ``create_engine()``.
This package includes:
@@ -50,94 +51,125 @@ url.py
within a URL.
"""
# not sure what this was used for
#import sqlalchemy.databases
from .interfaces import (
Connectable,
CreateEnginePlugin,
Dialect,
ExecutionContext,
ExceptionContext,
from sqlalchemy.engine.base import (
# backwards compat
Compiled,
TypeCompiler
)
from .base import (
Connection,
Engine,
NestedTransaction,
RootTransaction,
Transaction,
TwoPhaseTransaction,
)
from .result import (
BaseRowProxy,
BufferedColumnResultProxy,
BufferedColumnRow,
BufferedRowResultProxy,
Compiled,
Connectable,
Connection,
Dialect,
Engine,
ExecutionContext,
NestedTransaction,
FullyBufferedResultProxy,
ResultProxy,
RootTransaction,
RowProxy,
Transaction,
TwoPhaseTransaction,
TypeCompiler
)
from sqlalchemy.engine import strategies
from sqlalchemy import util
)
from .util import (
connection_memoize
)
__all__ = (
'BufferedColumnResultProxy',
'BufferedColumnRow',
'BufferedRowResultProxy',
'Compiled',
'Connectable',
'Connection',
'Dialect',
'Engine',
'ExecutionContext',
'NestedTransaction',
'ResultProxy',
'RootTransaction',
'RowProxy',
'Transaction',
'TwoPhaseTransaction',
'TypeCompiler',
'create_engine',
'engine_from_config',
)
from . import util, strategies
# backwards compat
from ..sql import ddl
default_strategy = 'plain'
def create_engine(*args, **kwargs):
"""Create a new Engine instance.
"""Create a new :class:`.Engine` instance.
The standard method of specifying the engine is via URL as the
first positional argument, to indicate the appropriate database
dialect and connection arguments, with additional keyword
arguments sent as options to the dialect and resulting Engine.
The standard calling form is to send the URL as the
first positional argument, usually a string
that indicates database dialect and connection arguments::
The URL is a string in the form
``dialect+driver://user:password@host/dbname[?key=value..]``, where
``dialect`` is a database name such as ``mysql``, ``oracle``,
``postgresql``, etc., and ``driver`` the name of a DBAPI, such as
``psycopg2``, ``pyodbc``, ``cx_oracle``, etc. Alternatively,
engine = create_engine("postgresql://scott:tiger@localhost/test")
Additional keyword arguments may then follow it which
establish various options on the resulting :class:`.Engine`
and its underlying :class:`.Dialect` and :class:`.Pool`
constructs::
engine = create_engine("mysql://scott:tiger@hostname/dbname",
encoding='latin1', echo=True)
The string form of the URL is
``dialect[+driver]://user:password@host/dbname[?key=value..]``, where
``dialect`` is a database name such as ``mysql``, ``oracle``,
``postgresql``, etc., and ``driver`` the name of a DBAPI, such as
``psycopg2``, ``pyodbc``, ``cx_oracle``, etc. Alternatively,
the URL can be an instance of :class:`~sqlalchemy.engine.url.URL`.
`**kwargs` takes a wide variety of options which are routed
towards their appropriate components. Arguments may be
specific to the Engine, the underlying Dialect, as well as the
Pool. Specific dialects also accept keyword arguments that
``**kwargs`` takes a wide variety of options which are routed
towards their appropriate components. Arguments may be specific to
the :class:`.Engine`, the underlying :class:`.Dialect`, as well as the
:class:`.Pool`. Specific dialects also accept keyword arguments that
are unique to that dialect. Here, we describe the parameters
that are common to most ``create_engine()`` usage.
that are common to most :func:`.create_engine()` usage.
:param assert_unicode: Deprecated. A warning is raised in all cases when a non-Unicode
object is passed when SQLAlchemy would coerce into an encoding
(note: but **not** when the DBAPI handles unicode objects natively).
To suppress or raise this warning to an
error, use the Python warnings filter documented at:
http://docs.python.org/library/warnings.html
Once established, the newly resulting :class:`.Engine` will
request a connection from the underlying :class:`.Pool` once
:meth:`.Engine.connect` is called, or a method which depends on it
such as :meth:`.Engine.execute` is invoked. The :class:`.Pool` in turn
will establish the first actual DBAPI connection when this request
is received. The :func:`.create_engine` call itself does **not**
establish any actual DBAPI connections directly.
.. seealso::
:doc:`/core/engines`
:doc:`/dialects/index`
:ref:`connections_toplevel`
:param case_sensitive=True: if False, result column names
will match in a case-insensitive fashion, that is,
``row['SomeColumn']``.
.. versionchanged:: 0.8
By default, result row names match case-sensitively.
In version 0.7 and prior, all matches were case-insensitive.
:param connect_args: a dictionary of options which will be
passed directly to the DBAPI's ``connect()`` method as
additional keyword arguments.
additional keyword arguments. See the example
at :ref:`custom_dbapi_args`.
:param convert_unicode=False: if set to True, all
String/character based types will convert Unicode values to raw
byte values going into the database, and all raw byte values to
Python Unicode coming out in result sets. This is an
engine-wide method to provide unicode conversion across the
board. For unicode conversion on a column-by-column level, use
the ``Unicode`` column type instead, described in `types`.
:param convert_unicode=False: if set to True, sets
the default behavior of ``convert_unicode`` on the
:class:`.String` type to ``True``, regardless
of a setting of ``False`` on an individual
:class:`.String` type, thus causing all :class:`.String`
-based columns
to accommodate Python ``unicode`` objects. This flag
is useful as an engine-wide setting when using a
DBAPI that does not natively support Python
``unicode`` objects and raises an error when
one is received (such as pyodbc with FreeTDS).
See :class:`.String` for further details on
what this flag indicates.
:param creator: a callable which returns a DBAPI connection.
This creation function will be passed to the underlying
@@ -160,23 +192,105 @@ def create_engine(*args, **kwargs):
:ref:`dbengine_logging` for information on how to configure logging
directly.
:param encoding='utf-8': the encoding to use for all Unicode
translations, both by engine-wide unicode conversion as well as
the ``Unicode`` type object.
:param encoding: Defaults to ``utf-8``. This is the string
encoding used by SQLAlchemy for string encode/decode
operations which occur within SQLAlchemy, **outside of
the DBAPI.** Most modern DBAPIs feature some degree of
direct support for Python ``unicode`` objects,
what you see in Python 2 as a string of the form
``u'some string'``. For those scenarios where the
DBAPI is detected as not supporting a Python ``unicode``
object, this encoding is used to determine the
source/destination encoding. It is **not used**
for those cases where the DBAPI handles unicode
directly.
To properly configure a system to accommodate Python
``unicode`` objects, the DBAPI should be
configured to handle unicode to the greatest
degree as is appropriate - see
the notes on unicode pertaining to the specific
target database in use at :ref:`dialect_toplevel`.
Areas where string encoding may need to be accommodated
outside of the DBAPI include zero or more of:
* the values passed to bound parameters, corresponding to
the :class:`.Unicode` type or the :class:`.String` type
when ``convert_unicode`` is ``True``;
* the values returned in result set columns corresponding
to the :class:`.Unicode` type or the :class:`.String`
type when ``convert_unicode`` is ``True``;
* the string SQL statement passed to the DBAPI's
``cursor.execute()`` method;
* the string names of the keys in the bound parameter
dictionary passed to the DBAPI's ``cursor.execute()``
as well as ``cursor.setinputsizes()`` methods;
* the string column names retrieved from the DBAPI's
``cursor.description`` attribute.
When using Python 3, the DBAPI is required to support
*all* of the above values as Python ``unicode`` objects,
which in Python 3 are just known as ``str``. In Python 2,
the DBAPI does not specify unicode behavior at all,
so SQLAlchemy must make decisions for each of the above
values on a per-DBAPI basis - implementations are
completely inconsistent in their behavior.
:param execution_options: Dictionary execution options which will
be applied to all connections. See
:meth:`~sqlalchemy.engine.Connection.execution_options`
:param implicit_returning=True: When ``True``, a RETURNING-
compatible construct, if available, will be used to
fetch newly generated primary key values when a single row
INSERT statement is emitted with no existing returning()
clause. This applies to those backends which support RETURNING
or a compatible construct, including PostgreSQL, Firebird, Oracle,
Microsoft SQL Server. Set this to ``False`` to disable
the automatic usage of RETURNING.
:param isolation_level: this string parameter is interpreted by various
dialects in order to affect the transaction isolation level of the
database connection. The parameter essentially accepts some subset of
these string arguments: ``"SERIALIZABLE"``, ``"REPEATABLE_READ"``,
``"READ_COMMITTED"``, ``"READ_UNCOMMITTED"`` and ``"AUTOCOMMIT"``.
Behavior here varies per backend, and
individual dialects should be consulted directly.
Note that the isolation level can also be set on a per-:class:`.Connection`
basis as well, using the
:paramref:`.Connection.execution_options.isolation_level`
feature.
.. seealso::
:attr:`.Connection.default_isolation_level` - view default level
:paramref:`.Connection.execution_options.isolation_level`
- set per :class:`.Connection` isolation level
:ref:`SQLite Transaction Isolation <sqlite_isolation_level>`
:ref:`PostgreSQL Transaction Isolation <postgresql_isolation_level>`
:ref:`MySQL Transaction Isolation <mysql_isolation_level>`
:ref:`session_transaction_isolation` - for the ORM
:param label_length=None: optional integer value which limits
the size of dynamically generated column labels to that many
characters. If less than 6, labels are generated as
"_(counter)". If ``None``, the value of
``dialect.max_identifier_length`` is used instead.
:param listeners: A list of one or more
:class:`~sqlalchemy.interfaces.PoolListener` objects which will
:param listeners: A list of one or more
:class:`~sqlalchemy.interfaces.PoolListener` objects which will
receive connection pool events.
:param logging_name: String identifier which will be used within
the "name" field of logging records generated within the
"sqlalchemy.engine" logger. Defaults to a hexstring of the
"sqlalchemy.engine" logger. Defaults to a hexstring of the
object's id.
:param max_overflow=10: the number of connections to allow in
@@ -184,10 +298,24 @@ def create_engine(*args, **kwargs):
opened above and beyond the pool_size setting, which defaults
to five. this is only used with :class:`~sqlalchemy.pool.QueuePool`.
:param module=None: used by database implementations which
support multiple DBAPI modules, this is a reference to a DBAPI2
module to be used instead of the engine's default module. For
PostgreSQL, the default is psycopg2. For Oracle, it's cx_Oracle.
:param module=None: reference to a Python module object (the module
itself, not its string name). Specifies an alternate DBAPI module to
be used by the engine's dialect. Each sub-dialect references a
specific DBAPI which will be imported before first connect. This
parameter causes the import to be bypassed, and the given module to
be used instead. Can be used for testing of DBAPIs as well as to
inject "mock" DBAPI implementations into the :class:`.Engine`.
:param paramstyle=None: The `paramstyle <http://legacy.python.org/dev/peps/pep-0249/#paramstyle>`_
to use when rendering bound parameters. This style defaults to the
one recommended by the DBAPI itself, which is retrieved from the
``.paramstyle`` attribute of the DBAPI. However, most DBAPIs accept
more than one paramstyle, and in particular it may be desirable
to change a "named" paramstyle into a "positional" one, or vice versa.
When this attribute is passed, it should be one of the values
``"qmark"``, ``"numeric"``, ``"named"``, ``"format"`` or
``"pyformat"``, and should correspond to a parameter style known
to be supported by the DBAPI in use.
:param pool=None: an already-constructed instance of
:class:`~sqlalchemy.pool.Pool`, such as a
@@ -195,7 +323,7 @@ def create_engine(*args, **kwargs):
pool will be used directly as the underlying connection pool
for the engine, bypassing whatever connection parameters are
present in the URL argument. For information on constructing
connection pools manually, see `pooling`.
connection pools manually, see :ref:`pooling_toplevel`.
:param poolclass=None: a :class:`~sqlalchemy.pool.Pool`
subclass, which will be used to create a connection pool
@@ -205,70 +333,102 @@ def create_engine(*args, **kwargs):
of pool to be used.
:param pool_logging_name: String identifier which will be used within
the "name" field of logging records generated within the
"sqlalchemy.pool" logger. Defaults to a hexstring of the object's
the "name" field of logging records generated within the
"sqlalchemy.pool" logger. Defaults to a hexstring of the object's
id.
:param pool_size=5: the number of connections to keep open
inside the connection pool. This used with :class:`~sqlalchemy.pool.QueuePool` as
well as :class:`~sqlalchemy.pool.SingletonThreadPool`.
inside the connection pool. This used with
:class:`~sqlalchemy.pool.QueuePool` as
well as :class:`~sqlalchemy.pool.SingletonThreadPool`. With
:class:`~sqlalchemy.pool.QueuePool`, a ``pool_size`` setting
of 0 indicates no limit; to disable pooling, set ``poolclass`` to
:class:`~sqlalchemy.pool.NullPool` instead.
:param pool_recycle=-1: this setting causes the pool to recycle
connections after the given number of seconds has passed. It
defaults to -1, or no timeout. For example, setting to 3600
means connections will be recycled after one hour. Note that
MySQL in particular will ``disconnect automatically`` if no
MySQL in particular will disconnect automatically if no
activity is detected on a connection for eight hours (although
this is configurable with the MySQLDB connection itself and the
server configuration as well).
:param pool_reset_on_return='rollback': set the "reset on return"
behavior of the pool, which is whether ``rollback()``,
``commit()``, or nothing is called upon connections
being returned to the pool. See the docstring for
``reset_on_return`` at :class:`.Pool`.
.. versionadded:: 0.7.6
:param pool_timeout=30: number of seconds to wait before giving
up on getting a connection from the pool. This is only used
with :class:`~sqlalchemy.pool.QueuePool`.
:param strategy='plain': used to invoke alternate :class:`~sqlalchemy.engine.base.Engine.`
implementations. Currently available is the ``threadlocal``
strategy, which is described in :ref:`threadlocal_strategy`.
:param strategy='plain': selects alternate engine implementations.
Currently available are:
* the ``threadlocal`` strategy, which is described in
:ref:`threadlocal_strategy`;
* the ``mock`` strategy, which dispatches all statement
execution to a function passed as the argument ``executor``.
See `example in the FAQ
<http://docs.sqlalchemy.org/en/latest/faq/metadata_schema.html#how-can-i-get-the-create-table-drop-table-output-as-a-string>`_.
:param executor=None: a function taking arguments
``(sql, *multiparams, **params)``, to which the ``mock`` strategy will
dispatch all statement execution. Used only by ``strategy='mock'``.
"""
strategy = kwargs.pop('strategy', default_strategy)
strategy = strategies.strategies[strategy]
return strategy.create(*args, **kwargs)
def engine_from_config(configuration, prefix='sqlalchemy.', **kwargs):
"""Create a new Engine instance using a configuration dictionary.
The dictionary is typically produced from a config file where keys
are prefixed, such as sqlalchemy.url, sqlalchemy.echo, etc. The
'prefix' argument indicates the prefix to be searched for.
The dictionary is typically produced from a config file.
The keys of interest to ``engine_from_config()`` should be prefixed, e.g.
``sqlalchemy.url``, ``sqlalchemy.echo``, etc. The 'prefix' argument
indicates the prefix to be searched for. Each matching key (after the
prefix is stripped) is treated as though it were the corresponding keyword
argument to a :func:`.create_engine` call.
The only required key is (assuming the default prefix) ``sqlalchemy.url``,
which provides the :ref:`database URL <database_urls>`.
A select set of keyword arguments will be "coerced" to their
expected type based on string values. In a future release, this
functionality will be expanded and include dialect-specific
arguments.
expected type based on string values. The set of arguments
is extensible per-dialect using the ``engine_config_types`` accessor.
:param configuration: A dictionary (typically produced from a config file,
but this is not a requirement). Items whose keys start with the value
of 'prefix' will have that prefix stripped, and will then be passed to
:ref:`create_engine`.
:param prefix: Prefix to match and then strip from keys
in 'configuration'.
:param kwargs: Each keyword argument to ``engine_from_config()`` itself
overrides the corresponding item taken from the 'configuration'
dictionary. Keyword arguments should *not* be prefixed.
"""
opts = _coerce_config(configuration, prefix)
opts.update(kwargs)
url = opts.pop('url')
return create_engine(url, **opts)
def _coerce_config(configuration, prefix):
"""Convert configuration values to expected types."""
options = dict((key[len(prefix):], configuration[key])
for key in configuration
if key.startswith(prefix))
for option, type_ in (
('convert_unicode', bool),
('pool_timeout', int),
('echo', bool),
('echo_pool', bool),
('pool_recycle', int),
('pool_size', int),
('max_overflow', int),
('pool_threadlocal', bool),
):
util.coerce_kw_type(options, option, type_)
return options
options['_coerce_config'] = True
options.update(kwargs)
url = options.pop('url')
return create_engine(url, **options)
__all__ = (
'create_engine',
'engine_from_config',
)

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sqlalchemy/engine/base.py
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sqlalchemy/engine/default.py
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787
sqlalchemy/engine/reflection.py
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@@ -1,3 +1,10 @@
# engine/reflection.py
# Copyright (C) 2005-2017 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""Provides an abstraction for obtaining database schema information.
Usage Notes:
@@ -18,11 +25,14 @@ methods such as get_table_names, get_columns, etc.
'name' attribute..
"""
import sqlalchemy
from sqlalchemy import exc, sql
from sqlalchemy import util
from sqlalchemy.types import TypeEngine
from sqlalchemy import schema as sa_schema
from .. import exc, sql
from ..sql import schema as sa_schema
from .. import util
from ..sql.type_api import TypeEngine
from ..util import deprecated
from ..util import topological
from .. import inspection
from .base import Connectable
@util.decorator
@@ -31,10 +41,14 @@ def cache(fn, self, con, *args, **kw):
if info_cache is None:
return fn(self, con, *args, **kw)
key = (
fn.__name__,
tuple(a for a in args if isinstance(a, basestring)),
tuple((k, v) for k, v in kw.iteritems() if isinstance(v, (basestring, int, float)))
)
fn.__name__,
tuple(a for a in args if isinstance(a, util.string_types)),
tuple((k, v) for k, v in kw.items() if
isinstance(v,
util.string_types + util.int_types + (float, )
)
)
)
ret = info_cache.get(key)
if ret is None:
ret = fn(self, con, *args, **kw)
@@ -45,33 +59,94 @@ def cache(fn, self, con, *args, **kw):
class Inspector(object):
"""Performs database schema inspection.
The Inspector acts as a proxy to the dialects' reflection methods and
provides higher level functions for accessing database schema information.
The Inspector acts as a proxy to the reflection methods of the
:class:`~sqlalchemy.engine.interfaces.Dialect`, providing a
consistent interface as well as caching support for previously
fetched metadata.
A :class:`.Inspector` object is usually created via the
:func:`.inspect` function::
from sqlalchemy import inspect, create_engine
engine = create_engine('...')
insp = inspect(engine)
The inspection method above is equivalent to using the
:meth:`.Inspector.from_engine` method, i.e.::
engine = create_engine('...')
insp = Inspector.from_engine(engine)
Where above, the :class:`~sqlalchemy.engine.interfaces.Dialect` may opt
to return an :class:`.Inspector` subclass that provides additional
methods specific to the dialect's target database.
"""
def __init__(self, conn):
"""Initialize the instance.
def __init__(self, bind):
"""Initialize a new :class:`.Inspector`.
:param bind: a :class:`~sqlalchemy.engine.Connectable`,
which is typically an instance of
:class:`~sqlalchemy.engine.Engine` or
:class:`~sqlalchemy.engine.Connection`.
For a dialect-specific instance of :class:`.Inspector`, see
:meth:`.Inspector.from_engine`
:param conn: a :class:`~sqlalchemy.engine.base.Connectable`
"""
# this might not be a connection, it could be an engine.
self.bind = bind
self.conn = conn
# set the engine
if hasattr(conn, 'engine'):
self.engine = conn.engine
if hasattr(bind, 'engine'):
self.engine = bind.engine
else:
self.engine = conn
self.engine = bind
if self.engine is bind:
# if engine, ensure initialized
bind.connect().close()
self.dialect = self.engine.dialect
self.info_cache = {}
@classmethod
def from_engine(cls, engine):
if hasattr(engine.dialect, 'inspector'):
return engine.dialect.inspector(engine)
return Inspector(engine)
def from_engine(cls, bind):
"""Construct a new dialect-specific Inspector object from the given
engine or connection.
:param bind: a :class:`~sqlalchemy.engine.Connectable`,
which is typically an instance of
:class:`~sqlalchemy.engine.Engine` or
:class:`~sqlalchemy.engine.Connection`.
This method differs from direct a direct constructor call of
:class:`.Inspector` in that the
:class:`~sqlalchemy.engine.interfaces.Dialect` is given a chance to
provide a dialect-specific :class:`.Inspector` instance, which may
provide additional methods.
See the example at :class:`.Inspector`.
"""
if hasattr(bind.dialect, 'inspector'):
return bind.dialect.inspector(bind)
return Inspector(bind)
@inspection._inspects(Connectable)
def _insp(bind):
return Inspector.from_engine(bind)
@property
def default_schema_name(self):
"""Return the default schema name presented by the dialect
for the current engine's database user.
E.g. this is typically ``public`` for PostgreSQL and ``dbo``
for SQL Server.
"""
return self.dialect.default_schema_name
def get_schema_names(self):
@@ -79,70 +154,185 @@ class Inspector(object):
"""
if hasattr(self.dialect, 'get_schema_names'):
return self.dialect.get_schema_names(self.conn,
info_cache=self.info_cache)
return self.dialect.get_schema_names(self.bind,
info_cache=self.info_cache)
return []
def get_table_names(self, schema=None, order_by=None):
"""Return all table names in `schema`.
"""Return all table names in referred to within a particular schema.
The names are expected to be real tables only, not views.
Views are instead returned using the :meth:`.Inspector.get_view_names`
method.
:param schema: Schema name. If ``schema`` is left at ``None``, the
database's default schema is
used, else the named schema is searched. If the database does not
support named schemas, behavior is undefined if ``schema`` is not
passed as ``None``. For special quoting, use :class:`.quoted_name`.
:param schema: Optional, retrieve names from a non-default schema.
:param order_by: Optional, may be the string "foreign_key" to sort
the result on foreign key dependencies.
the result on foreign key dependencies. Does not automatically
resolve cycles, and will raise :class:`.CircularDependencyError`
if cycles exist.
.. deprecated:: 1.0.0 - see
:meth:`.Inspector.get_sorted_table_and_fkc_names` for a version
of this which resolves foreign key cycles between tables
automatically.
.. versionchanged:: 0.8 the "foreign_key" sorting sorts tables
in order of dependee to dependent; that is, in creation
order, rather than in drop order. This is to maintain
consistency with similar features such as
:attr:`.MetaData.sorted_tables` and :func:`.util.sort_tables`.
.. seealso::
:meth:`.Inspector.get_sorted_table_and_fkc_names`
:attr:`.MetaData.sorted_tables`
This should probably not return view names or maybe it should return
them with an indicator t or v.
"""
if hasattr(self.dialect, 'get_table_names'):
tnames = self.dialect.get_table_names(self.conn,
schema,
info_cache=self.info_cache)
tnames = self.dialect.get_table_names(
self.bind, schema, info_cache=self.info_cache)
else:
tnames = self.engine.table_names(schema)
if order_by == 'foreign_key':
ordered_tnames = tnames[:]
# Order based on foreign key dependencies.
tuples = []
for tname in tnames:
table_pos = tnames.index(tname)
fkeys = self.get_foreign_keys(tname, schema)
for fkey in fkeys:
rtable = fkey['referred_table']
if rtable in ordered_tnames:
ref_pos = ordered_tnames.index(rtable)
# Make sure it's lower in the list than anything it
# references.
if table_pos > ref_pos:
ordered_tnames.pop(table_pos) # rtable moves up 1
# insert just below rtable
ordered_tnames.index(ref_pos, tname)
tnames = ordered_tnames
for fkey in self.get_foreign_keys(tname, schema):
if tname != fkey['referred_table']:
tuples.append((fkey['referred_table'], tname))
tnames = list(topological.sort(tuples, tnames))
return tnames
def get_sorted_table_and_fkc_names(self, schema=None):
"""Return dependency-sorted table and foreign key constraint names in
referred to within a particular schema.
This will yield 2-tuples of
``(tablename, [(tname, fkname), (tname, fkname), ...])``
consisting of table names in CREATE order grouped with the foreign key
constraint names that are not detected as belonging to a cycle.
The final element
will be ``(None, [(tname, fkname), (tname, fkname), ..])``
which will consist of remaining
foreign key constraint names that would require a separate CREATE
step after-the-fact, based on dependencies between tables.
.. versionadded:: 1.0.-
.. seealso::
:meth:`.Inspector.get_table_names`
:func:`.sort_tables_and_constraints` - similar method which works
with an already-given :class:`.MetaData`.
"""
if hasattr(self.dialect, 'get_table_names'):
tnames = self.dialect.get_table_names(
self.bind, schema, info_cache=self.info_cache)
else:
tnames = self.engine.table_names(schema)
tuples = set()
remaining_fkcs = set()
fknames_for_table = {}
for tname in tnames:
fkeys = self.get_foreign_keys(tname, schema)
fknames_for_table[tname] = set(
[fk['name'] for fk in fkeys]
)
for fkey in fkeys:
if tname != fkey['referred_table']:
tuples.add((fkey['referred_table'], tname))
try:
candidate_sort = list(topological.sort(tuples, tnames))
except exc.CircularDependencyError as err:
for edge in err.edges:
tuples.remove(edge)
remaining_fkcs.update(
(edge[1], fkc)
for fkc in fknames_for_table[edge[1]]
)
candidate_sort = list(topological.sort(tuples, tnames))
return [
(tname, fknames_for_table[tname].difference(remaining_fkcs))
for tname in candidate_sort
] + [(None, list(remaining_fkcs))]
def get_temp_table_names(self):
"""return a list of temporary table names for the current bind.
This method is unsupported by most dialects; currently
only SQLite implements it.
.. versionadded:: 1.0.0
"""
return self.dialect.get_temp_table_names(
self.bind, info_cache=self.info_cache)
def get_temp_view_names(self):
"""return a list of temporary view names for the current bind.
This method is unsupported by most dialects; currently
only SQLite implements it.
.. versionadded:: 1.0.0
"""
return self.dialect.get_temp_view_names(
self.bind, info_cache=self.info_cache)
def get_table_options(self, table_name, schema=None, **kw):
"""Return a dictionary of options specified when the table of the
given name was created.
This currently includes some options that apply to MySQL tables.
:param table_name: string name of the table. For special quoting,
use :class:`.quoted_name`.
:param schema: string schema name; if omitted, uses the default schema
of the database connection. For special quoting,
use :class:`.quoted_name`.
"""
if hasattr(self.dialect, 'get_table_options'):
return self.dialect.get_table_options(self.conn, table_name, schema,
info_cache=self.info_cache,
**kw)
return self.dialect.get_table_options(
self.bind, table_name, schema,
info_cache=self.info_cache, **kw)
return {}
def get_view_names(self, schema=None):
"""Return all view names in `schema`.
:param schema: Optional, retrieve names from a non-default schema.
For special quoting, use :class:`.quoted_name`.
"""
return self.dialect.get_view_names(self.conn, schema,
info_cache=self.info_cache)
return self.dialect.get_view_names(self.bind, schema,
info_cache=self.info_cache)
def get_view_definition(self, view_name, schema=None):
"""Return definition for `view_name`.
:param schema: Optional, retrieve names from a non-default schema.
For special quoting, use :class:`.quoted_name`.
"""
return self.dialect.get_view_definition(
self.conn, view_name, schema, info_cache=self.info_cache)
self.bind, view_name, schema, info_cache=self.info_cache)
def get_columns(self, table_name, schema=None, **kw):
"""Return information about columns in `table_name`.
@@ -150,23 +340,31 @@ class Inspector(object):
Given a string `table_name` and an optional string `schema`, return
column information as a list of dicts with these keys:
name
the column's name
* ``name`` - the column's name
type
* ``type`` - the type of this column; an instance of
:class:`~sqlalchemy.types.TypeEngine`
nullable
boolean
* ``nullable`` - boolean flag if the column is NULL or NOT NULL
default
the column's default value
* ``default`` - the column's server default value - this is returned
as a string SQL expression.
* ``attrs`` - dict containing optional column attributes
:param table_name: string name of the table. For special quoting,
use :class:`.quoted_name`.
:param schema: string schema name; if omitted, uses the default schema
of the database connection. For special quoting,
use :class:`.quoted_name`.
:return: list of dictionaries, each representing the definition of
a database column.
attrs
dict containing optional column attributes
"""
col_defs = self.dialect.get_columns(self.conn, table_name, schema,
col_defs = self.dialect.get_columns(self.bind, table_name, schema,
info_cache=self.info_cache,
**kw)
for col_def in col_defs:
@@ -176,6 +374,8 @@ class Inspector(object):
col_def['type'] = coltype()
return col_defs
@deprecated('0.7', 'Call to deprecated method get_primary_keys.'
' Use get_pk_constraint instead.')
def get_primary_keys(self, table_name, schema=None, **kw):
"""Return information about primary keys in `table_name`.
@@ -183,12 +383,34 @@ class Inspector(object):
primary key information as a list of column names.
"""
pkeys = self.dialect.get_primary_keys(self.conn, table_name, schema,
return self.dialect.get_pk_constraint(self.bind, table_name, schema,
info_cache=self.info_cache,
**kw)['constrained_columns']
def get_pk_constraint(self, table_name, schema=None, **kw):
"""Return information about primary key constraint on `table_name`.
Given a string `table_name`, and an optional string `schema`, return
primary key information as a dictionary with these keys:
constrained_columns
a list of column names that make up the primary key
name
optional name of the primary key constraint.
:param table_name: string name of the table. For special quoting,
use :class:`.quoted_name`.
:param schema: string schema name; if omitted, uses the default schema
of the database connection. For special quoting,
use :class:`.quoted_name`.
"""
return self.dialect.get_pk_constraint(self.bind, table_name, schema,
info_cache=self.info_cache,
**kw)
return pkeys
def get_foreign_keys(self, table_name, schema=None, **kw):
"""Return information about foreign_keys in `table_name`.
@@ -208,15 +430,21 @@ class Inspector(object):
a list of column names in the referred table that correspond to
constrained_columns
\**kw
other options passed to the dialect's get_foreign_keys() method.
name
optional name of the foreign key constraint.
:param table_name: string name of the table. For special quoting,
use :class:`.quoted_name`.
:param schema: string schema name; if omitted, uses the default schema
of the database connection. For special quoting,
use :class:`.quoted_name`.
"""
fk_defs = self.dialect.get_foreign_keys(self.conn, table_name, schema,
info_cache=self.info_cache,
**kw)
return fk_defs
return self.dialect.get_foreign_keys(self.bind, table_name, schema,
info_cache=self.info_cache,
**kw)
def get_indexes(self, table_name, schema=None, **kw):
"""Return information about indexes in `table_name`.
@@ -232,104 +460,261 @@ class Inspector(object):
unique
boolean
\**kw
other options passed to the dialect's get_indexes() method.
dialect_options
dict of dialect-specific index options. May not be present
for all dialects.
.. versionadded:: 1.0.0
:param table_name: string name of the table. For special quoting,
use :class:`.quoted_name`.
:param schema: string schema name; if omitted, uses the default schema
of the database connection. For special quoting,
use :class:`.quoted_name`.
"""
indexes = self.dialect.get_indexes(self.conn, table_name,
schema,
info_cache=self.info_cache, **kw)
return indexes
return self.dialect.get_indexes(self.bind, table_name,
schema,
info_cache=self.info_cache, **kw)
def reflecttable(self, table, include_columns):
def get_unique_constraints(self, table_name, schema=None, **kw):
"""Return information about unique constraints in `table_name`.
dialect = self.conn.dialect
Given a string `table_name` and an optional string `schema`, return
unique constraint information as a list of dicts with these keys:
# MySQL dialect does this. Applicable with other dialects?
if hasattr(dialect, '_connection_charset') \
and hasattr(dialect, '_adjust_casing'):
charset = dialect._connection_charset
dialect._adjust_casing(table)
name
the unique constraint's name
# table attributes we might need.
reflection_options = dict(
(k, table.kwargs.get(k)) for k in dialect.reflection_options if k in table.kwargs)
column_names
list of column names in order
:param table_name: string name of the table. For special quoting,
use :class:`.quoted_name`.
:param schema: string schema name; if omitted, uses the default schema
of the database connection. For special quoting,
use :class:`.quoted_name`.
.. versionadded:: 0.8.4
"""
return self.dialect.get_unique_constraints(
self.bind, table_name, schema, info_cache=self.info_cache, **kw)
def get_check_constraints(self, table_name, schema=None, **kw):
"""Return information about check constraints in `table_name`.
Given a string `table_name` and an optional string `schema`, return
check constraint information as a list of dicts with these keys:
name
the check constraint's name
sqltext
the check constraint's SQL expression
:param table_name: string name of the table. For special quoting,
use :class:`.quoted_name`.
:param schema: string schema name; if omitted, uses the default schema
of the database connection. For special quoting,
use :class:`.quoted_name`.
.. versionadded:: 1.1.0
"""
return self.dialect.get_check_constraints(
self.bind, table_name, schema, info_cache=self.info_cache, **kw)
def reflecttable(self, table, include_columns, exclude_columns=(),
_extend_on=None):
"""Given a Table object, load its internal constructs based on
introspection.
This is the underlying method used by most dialects to produce
table reflection. Direct usage is like::
from sqlalchemy import create_engine, MetaData, Table
from sqlalchemy.engine import reflection
engine = create_engine('...')
meta = MetaData()
user_table = Table('user', meta)
insp = Inspector.from_engine(engine)
insp.reflecttable(user_table, None)
:param table: a :class:`~sqlalchemy.schema.Table` instance.
:param include_columns: a list of string column names to include
in the reflection process. If ``None``, all columns are reflected.
"""
if _extend_on is not None:
if table in _extend_on:
return
else:
_extend_on.add(table)
dialect = self.bind.dialect
schema = self.bind.schema_for_object(table)
schema = table.schema
table_name = table.name
# apply table options
tbl_opts = self.get_table_options(table_name, schema, **table.kwargs)
# get table-level arguments that are specifically
# intended for reflection, e.g. oracle_resolve_synonyms.
# these are unconditionally passed to related Table
# objects
reflection_options = dict(
(k, table.dialect_kwargs.get(k))
for k in dialect.reflection_options
if k in table.dialect_kwargs
)
# reflect table options, like mysql_engine
tbl_opts = self.get_table_options(
table_name, schema, **table.dialect_kwargs)
if tbl_opts:
table.kwargs.update(tbl_opts)
# add additional kwargs to the Table if the dialect
# returned them
table._validate_dialect_kwargs(tbl_opts)
# table.kwargs will need to be passed to each reflection method. Make
# sure keywords are strings.
tblkw = table.kwargs.copy()
for (k, v) in tblkw.items():
del tblkw[k]
tblkw[str(k)] = v
if util.py2k:
if isinstance(schema, str):
schema = schema.decode(dialect.encoding)
if isinstance(table_name, str):
table_name = table_name.decode(dialect.encoding)
# Py2K
if isinstance(schema, str):
schema = schema.decode(dialect.encoding)
if isinstance(table_name, str):
table_name = table_name.decode(dialect.encoding)
# end Py2K
# columns
found_table = False
for col_d in self.get_columns(table_name, schema, **tblkw):
found_table = True
name = col_d['name']
if include_columns and name not in include_columns:
continue
cols_by_orig_name = {}
coltype = col_d['type']
col_kw = {
'nullable':col_d['nullable'],
}
if 'autoincrement' in col_d:
col_kw['autoincrement'] = col_d['autoincrement']
if 'quote' in col_d:
col_kw['quote'] = col_d['quote']
colargs = []
if col_d.get('default') is not None:
# the "default" value is assumed to be a literal SQL expression,
# so is wrapped in text() so that no quoting occurs on re-issuance.
colargs.append(sa_schema.DefaultClause(sql.text(col_d['default'])))
if 'sequence' in col_d:
# TODO: mssql, maxdb and sybase are using this.
seq = col_d['sequence']
sequence = sa_schema.Sequence(seq['name'], 1, 1)
if 'start' in seq:
sequence.start = seq['start']
if 'increment' in seq:
sequence.increment = seq['increment']
colargs.append(sequence)
col = sa_schema.Column(name, coltype, *colargs, **col_kw)
table.append_column(col)
for col_d in self.get_columns(
table_name, schema, **table.dialect_kwargs):
found_table = True
self._reflect_column(
table, col_d, include_columns,
exclude_columns, cols_by_orig_name)
if not found_table:
raise exc.NoSuchTableError(table.name)
# Primary keys
primary_key_constraint = sa_schema.PrimaryKeyConstraint(*[
table.c[pk] for pk in self.get_primary_keys(table_name, schema, **tblkw)
if pk in table.c
])
self._reflect_pk(
table_name, schema, table, cols_by_orig_name, exclude_columns)
table.append_constraint(primary_key_constraint)
self._reflect_fk(
table_name, schema, table, cols_by_orig_name,
exclude_columns, _extend_on, reflection_options)
# Foreign keys
fkeys = self.get_foreign_keys(table_name, schema, **tblkw)
self._reflect_indexes(
table_name, schema, table, cols_by_orig_name,
include_columns, exclude_columns, reflection_options)
self._reflect_unique_constraints(
table_name, schema, table, cols_by_orig_name,
include_columns, exclude_columns, reflection_options)
self._reflect_check_constraints(
table_name, schema, table, cols_by_orig_name,
include_columns, exclude_columns, reflection_options)
def _reflect_column(
self, table, col_d, include_columns,
exclude_columns, cols_by_orig_name):
orig_name = col_d['name']
table.dispatch.column_reflect(self, table, col_d)
# fetch name again as column_reflect is allowed to
# change it
name = col_d['name']
if (include_columns and name not in include_columns) \
or (exclude_columns and name in exclude_columns):
return
coltype = col_d['type']
col_kw = dict(
(k, col_d[k])
for k in ['nullable', 'autoincrement', 'quote', 'info', 'key']
if k in col_d
)
colargs = []
if col_d.get('default') is not None:
default = col_d['default']
if isinstance(default, sql.elements.TextClause):
default = sa_schema.DefaultClause(default, _reflected=True)
elif not isinstance(default, sa_schema.FetchedValue):
default = sa_schema.DefaultClause(
sql.text(col_d['default']), _reflected=True)
colargs.append(default)
if 'sequence' in col_d:
self._reflect_col_sequence(col_d, colargs)
cols_by_orig_name[orig_name] = col = \
sa_schema.Column(name, coltype, *colargs, **col_kw)
if col.key in table.primary_key:
col.primary_key = True
table.append_column(col)
def _reflect_col_sequence(self, col_d, colargs):
if 'sequence' in col_d:
# TODO: mssql and sybase are using this.
seq = col_d['sequence']
sequence = sa_schema.Sequence(seq['name'], 1, 1)
if 'start' in seq:
sequence.start = seq['start']
if 'increment' in seq:
sequence.increment = seq['increment']
colargs.append(sequence)
def _reflect_pk(
self, table_name, schema, table,
cols_by_orig_name, exclude_columns):
pk_cons = self.get_pk_constraint(
table_name, schema, **table.dialect_kwargs)
if pk_cons:
pk_cols = [
cols_by_orig_name[pk]
for pk in pk_cons['constrained_columns']
if pk in cols_by_orig_name and pk not in exclude_columns
]
# update pk constraint name
table.primary_key.name = pk_cons.get('name')
# tell the PKConstraint to re-initialize
# its column collection
table.primary_key._reload(pk_cols)
def _reflect_fk(
self, table_name, schema, table, cols_by_orig_name,
exclude_columns, _extend_on, reflection_options):
fkeys = self.get_foreign_keys(
table_name, schema, **table.dialect_kwargs)
for fkey_d in fkeys:
conname = fkey_d['name']
constrained_columns = fkey_d['constrained_columns']
# look for columns by orig name in cols_by_orig_name,
# but support columns that are in-Python only as fallback
constrained_columns = [
cols_by_orig_name[c].key
if c in cols_by_orig_name else c
for c in fkey_d['constrained_columns']
]
if exclude_columns and set(constrained_columns).intersection(
exclude_columns):
continue
referred_schema = fkey_d['referred_schema']
referred_table = fkey_d['referred_table']
referred_columns = fkey_d['referred_columns']
@@ -337,7 +722,8 @@ class Inspector(object):
if referred_schema is not None:
sa_schema.Table(referred_table, table.metadata,
autoload=True, schema=referred_schema,
autoload_with=self.conn,
autoload_with=self.bind,
_extend_on=_extend_on,
**reflection_options
)
for column in referred_columns:
@@ -345,26 +731,113 @@ class Inspector(object):
[referred_schema, referred_table, column]))
else:
sa_schema.Table(referred_table, table.metadata, autoload=True,
autoload_with=self.conn,
autoload_with=self.bind,
schema=sa_schema.BLANK_SCHEMA,
_extend_on=_extend_on,
**reflection_options
)
for column in referred_columns:
refspec.append(".".join([referred_table, column]))
if 'options' in fkey_d:
options = fkey_d['options']
else:
options = {}
table.append_constraint(
sa_schema.ForeignKeyConstraint(constrained_columns, refspec,
conname, link_to_name=True))
# Indexes
conname, link_to_name=True,
**options))
def _reflect_indexes(
self, table_name, schema, table, cols_by_orig_name,
include_columns, exclude_columns, reflection_options):
# Indexes
indexes = self.get_indexes(table_name, schema)
for index_d in indexes:
name = index_d['name']
columns = index_d['column_names']
unique = index_d['unique']
flavor = index_d.get('type', 'unknown type')
flavor = index_d.get('type', 'index')
dialect_options = index_d.get('dialect_options', {})
duplicates = index_d.get('duplicates_constraint')
if include_columns and \
not set(columns).issubset(include_columns):
not set(columns).issubset(include_columns):
util.warn(
"Omitting %s KEY for (%s), key covers omitted columns." %
"Omitting %s key for (%s), key covers omitted columns." %
(flavor, ', '.join(columns)))
continue
sa_schema.Index(name, *[table.columns[c] for c in columns],
**dict(unique=unique))
if duplicates:
continue
# look for columns by orig name in cols_by_orig_name,
# but support columns that are in-Python only as fallback
idx_cols = []
for c in columns:
try:
idx_col = cols_by_orig_name[c] \
if c in cols_by_orig_name else table.c[c]
except KeyError:
util.warn(
"%s key '%s' was not located in "
"columns for table '%s'" % (
flavor, c, table_name
))
else:
idx_cols.append(idx_col)
sa_schema.Index(
name, *idx_cols,
**dict(list(dialect_options.items()) + [('unique', unique)])
)
def _reflect_unique_constraints(
self, table_name, schema, table, cols_by_orig_name,
include_columns, exclude_columns, reflection_options):
# Unique Constraints
try:
constraints = self.get_unique_constraints(table_name, schema)
except NotImplementedError:
# optional dialect feature
return
for const_d in constraints:
conname = const_d['name']
columns = const_d['column_names']
duplicates = const_d.get('duplicates_index')
if include_columns and \
not set(columns).issubset(include_columns):
util.warn(
"Omitting unique constraint key for (%s), "
"key covers omitted columns." %
', '.join(columns))
continue
if duplicates:
continue
# look for columns by orig name in cols_by_orig_name,
# but support columns that are in-Python only as fallback
constrained_cols = []
for c in columns:
try:
constrained_col = cols_by_orig_name[c] \
if c in cols_by_orig_name else table.c[c]
except KeyError:
util.warn(
"unique constraint key '%s' was not located in "
"columns for table '%s'" % (c, table_name))
else:
constrained_cols.append(constrained_col)
table.append_constraint(
sa_schema.UniqueConstraint(*constrained_cols, name=conname))
def _reflect_check_constraints(
self, table_name, schema, table, cols_by_orig_name,
include_columns, exclude_columns, reflection_options):
try:
constraints = self.get_check_constraints(table_name, schema)
except NotImplementedError:
# optional dialect feature
return
for const_d in constraints:
table.append_constraint(
sa_schema.CheckConstraint(**const_d))

154
sqlalchemy/engine/strategies.py
View File

@@ -1,3 +1,10 @@
# engine/strategies.py
# Copyright (C) 2005-2017 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""Strategies for creating new instances of Engine types.
These are semi-private implementation classes which provide the
@@ -11,18 +18,19 @@ New strategies can be added via new ``EngineStrategy`` classes.
from operator import attrgetter
from sqlalchemy.engine import base, threadlocal, url
from sqlalchemy import util, exc
from sqlalchemy import util, event
from sqlalchemy import pool as poollib
from sqlalchemy.sql import schema
strategies = {}
class EngineStrategy(object):
"""An adaptor that processes input arguements and produces an Engine.
"""An adaptor that processes input arguments and produces an Engine.
Provides a ``create`` method that receives input arguments and
produces an instance of base.Engine or a subclass.
"""
def __init__(self):
@@ -35,58 +43,75 @@ class EngineStrategy(object):
class DefaultEngineStrategy(EngineStrategy):
"""Base class for built-in stratgies."""
"""Base class for built-in strategies."""
pool_threadlocal = False
def create(self, name_or_url, **kwargs):
# create url.URL object
u = url.make_url(name_or_url)
dialect_cls = u.get_dialect()
plugins = u._instantiate_plugins(kwargs)
u.query.pop('plugin', None)
entrypoint = u._get_entrypoint()
dialect_cls = entrypoint.get_dialect_cls(u)
if kwargs.pop('_coerce_config', False):
def pop_kwarg(key, default=None):
value = kwargs.pop(key, default)
if key in dialect_cls.engine_config_types:
value = dialect_cls.engine_config_types[key](value)
return value
else:
pop_kwarg = kwargs.pop
dialect_args = {}
# consume dialect arguments from kwargs
for k in util.get_cls_kwargs(dialect_cls):
if k in kwargs:
dialect_args[k] = kwargs.pop(k)
dialect_args[k] = pop_kwarg(k)
dbapi = kwargs.pop('module', None)
if dbapi is None:
dbapi_args = {}
for k in util.get_func_kwargs(dialect_cls.dbapi):
if k in kwargs:
dbapi_args[k] = kwargs.pop(k)
dbapi_args[k] = pop_kwarg(k)
dbapi = dialect_cls.dbapi(**dbapi_args)
dialect_args['dbapi'] = dbapi
for plugin in plugins:
plugin.handle_dialect_kwargs(dialect_cls, dialect_args)
# create dialect
dialect = dialect_cls(**dialect_args)
# assemble connection arguments
(cargs, cparams) = dialect.create_connect_args(u)
cparams.update(kwargs.pop('connect_args', {}))
cparams.update(pop_kwarg('connect_args', {}))
cargs = list(cargs) # allow mutability
# look for existing pool or create
pool = kwargs.pop('pool', None)
pool = pop_kwarg('pool', None)
if pool is None:
def connect():
try:
return dialect.connect(*cargs, **cparams)
except Exception, e:
# Py3K
#raise exc.DBAPIError.instance(None, None, e) from e
# Py2K
import sys
raise exc.DBAPIError.instance(None, None, e), None, sys.exc_info()[2]
# end Py2K
creator = kwargs.pop('creator', connect)
def connect(connection_record=None):
if dialect._has_events:
for fn in dialect.dispatch.do_connect:
connection = fn(
dialect, connection_record, cargs, cparams)
if connection is not None:
return connection
return dialect.connect(*cargs, **cparams)
poolclass = (kwargs.pop('poolclass', None) or
getattr(dialect_cls, 'poolclass', poollib.QueuePool))
pool_args = {}
creator = pop_kwarg('creator', connect)
poolclass = pop_kwarg('poolclass', None)
if poolclass is None:
poolclass = dialect_cls.get_pool_class(u)
pool_args = {
'dialect': dialect
}
# consume pool arguments from kwargs, translating a few of
# the arguments
@@ -94,12 +119,17 @@ class DefaultEngineStrategy(EngineStrategy):
'echo': 'echo_pool',
'timeout': 'pool_timeout',
'recycle': 'pool_recycle',
'use_threadlocal':'pool_threadlocal'}
'events': 'pool_events',
'use_threadlocal': 'pool_threadlocal',
'reset_on_return': 'pool_reset_on_return'}
for k in util.get_cls_kwargs(poolclass):
tk = translate.get(k, k)
if tk in kwargs:
pool_args[k] = kwargs.pop(tk)
pool_args.setdefault('use_threadlocal', self.pool_threadlocal)
pool_args[k] = pop_kwarg(tk)
for plugin in plugins:
plugin.handle_pool_kwargs(poolclass, pool_args)
pool = poolclass(creator, **pool_args)
else:
if isinstance(pool, poollib._DBProxy):
@@ -107,15 +137,17 @@ class DefaultEngineStrategy(EngineStrategy):
else:
pool = pool
pool._dialect = dialect
# create engine.
engineclass = self.engine_cls
engine_args = {}
for k in util.get_cls_kwargs(engineclass):
if k in kwargs:
engine_args[k] = kwargs.pop(k)
engine_args[k] = pop_kwarg(k)
_initialize = kwargs.pop('_initialize', True)
# all kwargs should be consumed
if kwargs:
raise TypeError(
@@ -126,24 +158,35 @@ class DefaultEngineStrategy(EngineStrategy):
dialect.__class__.__name__,
pool.__class__.__name__,
engineclass.__name__))
engine = engineclass(pool, dialect, u, **engine_args)
if _initialize:
do_on_connect = dialect.on_connect()
if do_on_connect:
def on_connect(conn, rec):
conn = getattr(conn, '_sqla_unwrap', conn)
def on_connect(dbapi_connection, connection_record):
conn = getattr(
dbapi_connection, '_sqla_unwrap', dbapi_connection)
if conn is None:
return
do_on_connect(conn)
pool.add_listener({'first_connect': on_connect, 'connect':on_connect})
def first_connect(conn, rec):
c = base.Connection(engine, connection=conn)
event.listen(pool, 'first_connect', on_connect)
event.listen(pool, 'connect', on_connect)
def first_connect(dbapi_connection, connection_record):
c = base.Connection(engine, connection=dbapi_connection,
_has_events=False)
c._execution_options = util.immutabledict()
dialect.initialize(c)
pool.add_listener({'first_connect':first_connect})
event.listen(pool, 'first_connect', first_connect, once=True)
dialect_cls.engine_created(engine)
if entrypoint is not dialect_cls:
entrypoint.engine_created(engine)
for plugin in plugins:
plugin.engine_created(engine)
return engine
@@ -153,15 +196,14 @@ class PlainEngineStrategy(DefaultEngineStrategy):
name = 'plain'
engine_cls = base.Engine
PlainEngineStrategy()
class ThreadLocalEngineStrategy(DefaultEngineStrategy):
"""Strategy for configuring an Engine with thredlocal behavior."""
"""Strategy for configuring an Engine with threadlocal behavior."""
name = 'threadlocal'
pool_threadlocal = True
engine_cls = threadlocal.TLEngine
ThreadLocalEngineStrategy()
@@ -172,11 +214,11 @@ class MockEngineStrategy(EngineStrategy):
Produces a single mock Connectable object which dispatches
statement execution to a passed-in function.
"""
name = 'mock'
def create(self, name_or_url, executor, **kwargs):
# create url.URL object
u = url.make_url(name_or_url)
@@ -203,9 +245,14 @@ class MockEngineStrategy(EngineStrategy):
dialect = property(attrgetter('_dialect'))
name = property(lambda s: s._dialect.name)
schema_for_object = schema._schema_getter(None)
def contextual_connect(self, **kwargs):
return self
def execution_options(self, **kw):
return self
def compiler(self, statement, parameters, **kwargs):
return self._dialect.compiler(
statement, parameters, engine=self, **kwargs)
@@ -213,13 +260,22 @@ class MockEngineStrategy(EngineStrategy):
def create(self, entity, **kwargs):
kwargs['checkfirst'] = False
from sqlalchemy.engine import ddl
ddl.SchemaGenerator(self.dialect, self, **kwargs).traverse(entity)
ddl.SchemaGenerator(
self.dialect, self, **kwargs).traverse_single(entity)
def drop(self, entity, **kwargs):
kwargs['checkfirst'] = False
from sqlalchemy.engine import ddl
ddl.SchemaDropper(self.dialect, self, **kwargs).traverse(entity)
ddl.SchemaDropper(
self.dialect, self, **kwargs).traverse_single(entity)
def _run_visitor(self, visitorcallable, element,
connection=None,
**kwargs):
kwargs['checkfirst'] = False
visitorcallable(self.dialect, self,
**kwargs).traverse_single(element)
def execute(self, object, *multiparams, **params):
raise NotImplementedError()

101
sqlalchemy/engine/threadlocal.py
View File

@@ -1,23 +1,33 @@
# engine/threadlocal.py
# Copyright (C) 2005-2017 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""Provides a thread-local transactional wrapper around the root Engine class.
The ``threadlocal`` module is invoked when using the ``strategy="threadlocal"`` flag
with :func:`~sqlalchemy.engine.create_engine`. This module is semi-private and is
invoked automatically when the threadlocal engine strategy is used.
The ``threadlocal`` module is invoked when using the
``strategy="threadlocal"`` flag with :func:`~sqlalchemy.engine.create_engine`.
This module is semi-private and is invoked automatically when the threadlocal
engine strategy is used.
"""
from sqlalchemy import util
from sqlalchemy.engine import base
from .. import util
from . import base
import weakref
class TLConnection(base.Connection):
def __init__(self, *arg, **kw):
super(TLConnection, self).__init__(*arg, **kw)
self.__opencount = 0
def _increment_connect(self):
self.__opencount += 1
return self
def close(self):
if self.__opencount == 1:
base.Connection.close(self)
@@ -27,70 +37,95 @@ class TLConnection(base.Connection):
self.__opencount = 0
base.Connection.close(self)
class TLEngine(base.Engine):
"""An Engine that includes support for thread-local managed transactions."""
class TLEngine(base.Engine):
"""An Engine that includes support for thread-local managed
transactions.
"""
_tl_connection_cls = TLConnection
def __init__(self, *args, **kwargs):
super(TLEngine, self).__init__(*args, **kwargs)
self._connections = util.threading.local()
proxy = kwargs.get('proxy')
if proxy:
self.TLConnection = base._proxy_connection_cls(TLConnection, proxy)
else:
self.TLConnection = TLConnection
def contextual_connect(self, **kw):
if not hasattr(self._connections, 'conn'):
connection = None
else:
connection = self._connections.conn()
if connection is None or connection.closed:
# guards against pool-level reapers, if desired.
# or not connection.connection.is_valid:
connection = self.TLConnection(self, self.pool.connect(), **kw)
self._connections.conn = conn = weakref.ref(connection)
connection = self._tl_connection_cls(
self,
self._wrap_pool_connect(
self.pool.connect, connection),
**kw)
self._connections.conn = weakref.ref(connection)
return connection._increment_connect()
def begin_twophase(self, xid=None):
if not hasattr(self._connections, 'trans'):
self._connections.trans = []
self._connections.trans.append(self.contextual_connect().begin_twophase(xid=xid))
self._connections.trans.append(
self.contextual_connect().begin_twophase(xid=xid))
return self
def begin_nested(self):
if not hasattr(self._connections, 'trans'):
self._connections.trans = []
self._connections.trans.append(self.contextual_connect().begin_nested())
self._connections.trans.append(
self.contextual_connect().begin_nested())
return self
def begin(self):
if not hasattr(self._connections, 'trans'):
self._connections.trans = []
self._connections.trans.append(self.contextual_connect().begin())
return self
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
if type is None:
self.commit()
else:
self.rollback()
def prepare(self):
if not hasattr(self._connections, 'trans') or \
not self._connections.trans:
return
self._connections.trans[-1].prepare()
def commit(self):
if not hasattr(self._connections, 'trans') or \
not self._connections.trans:
return
trans = self._connections.trans.pop(-1)
trans.commit()
def rollback(self):
if not hasattr(self._connections, 'trans') or \
not self._connections.trans:
return
trans = self._connections.trans.pop(-1)
trans.rollback()
def dispose(self):
self._connections = util.threading.local()
super(TLEngine, self).dispose()
@property
def closed(self):
return not hasattr(self._connections, 'conn') or \
self._connections.conn() is None or \
self._connections.conn().closed
self._connections.conn() is None or \
self._connections.conn().closed
def close(self):
if not self.closed:
self.contextual_connect().close()
@@ -98,6 +133,6 @@ class TLEngine(base.Engine):
connection._force_close()
del self._connections.conn
self._connections.trans = []
def __repr__(self):
return 'TLEngine(%s)' % str(self.url)
return 'TLEngine(%r)' % self.url

173
sqlalchemy/engine/url.py
View File

@@ -1,13 +1,23 @@
# engine/url.py
# Copyright (C) 2005-2017 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""Provides the :class:`~sqlalchemy.engine.url.URL` class which encapsulates
information about a database connection specification.
The URL object is created automatically when :func:`~sqlalchemy.engine.create_engine` is called
with a string argument; alternatively, the URL is a public-facing construct which can
The URL object is created automatically when
:func:`~sqlalchemy.engine.create_engine` is called with a string
argument; alternatively, the URL is a public-facing construct which can
be used directly and is also accepted directly by ``create_engine()``.
"""
import re, cgi, sys, urllib
from sqlalchemy import exc
import re
from .. import exc, util
from . import Dialect
from ..dialects import registry, plugins
class URL(object):
@@ -15,8 +25,8 @@ class URL(object):
Represent the components of a URL used to connect to a database.
This object is suitable to be passed directly to a
``create_engine()`` call. The fields of the URL are parsed from a
string by the ``module-level make_url()`` function. the string
:func:`~sqlalchemy.create_engine` call. The fields of the URL are parsed
from a string by the :func:`.make_url` function. the string
format of the URL is an RFC-1738-style string.
All initialization parameters are available as public attributes.
@@ -53,25 +63,35 @@ class URL(object):
self.database = database
self.query = query or {}
def __str__(self):
def __to_string__(self, hide_password=True):
s = self.drivername + "://"
if self.username is not None:
s += self.username
s += _rfc_1738_quote(self.username)
if self.password is not None:
s += ':' + urllib.quote_plus(self.password)
s += ':' + ('***' if hide_password
else _rfc_1738_quote(self.password))
s += "@"
if self.host is not None:
s += self.host
if ':' in self.host:
s += "[%s]" % self.host
else:
s += self.host
if self.port is not None:
s += ':' + str(self.port)
if self.database is not None:
s += '/' + self.database
if self.query:
keys = self.query.keys()
keys = list(self.query)
keys.sort()
s += '?' + "&".join("%s=%s" % (k, self.query[k]) for k in keys)
return s
def __str__(self):
return self.__to_string__(hide_password=False)
def __repr__(self):
return self.__to_string__()
def __hash__(self):
return hash(str(self))
@@ -85,49 +105,58 @@ class URL(object):
self.database == other.database and \
self.query == other.query
def get_backend_name(self):
if '+' not in self.drivername:
return self.drivername
else:
return self.drivername.split('+')[0]
def get_driver_name(self):
if '+' not in self.drivername:
return self.get_dialect().driver
else:
return self.drivername.split('+')[1]
def _instantiate_plugins(self, kwargs):
plugin_names = util.to_list(self.query.get('plugin', ()))
return [
plugins.load(plugin_name)(self, kwargs)
for plugin_name in plugin_names
]
def _get_entrypoint(self):
"""Return the "entry point" dialect class.
This is normally the dialect itself except in the case when the
returned class implements the get_dialect_cls() method.
"""
if '+' not in self.drivername:
name = self.drivername
else:
name = self.drivername.replace('+', '.')
cls = registry.load(name)
# check for legacy dialects that
# would return a module with 'dialect' as the
# actual class
if hasattr(cls, 'dialect') and \
isinstance(cls.dialect, type) and \
issubclass(cls.dialect, Dialect):
return cls.dialect
else:
return cls
def get_dialect(self):
"""Return the SQLAlchemy database dialect class corresponding
to this URL's driver name.
"""
entrypoint = self._get_entrypoint()
dialect_cls = entrypoint.get_dialect_cls(self)
return dialect_cls
try:
if '+' in self.drivername:
dialect, driver = self.drivername.split('+')
else:
dialect, driver = self.drivername, 'base'
module = __import__('sqlalchemy.dialects.%s' % (dialect, )).dialects
module = getattr(module, dialect)
module = getattr(module, driver)
return module.dialect
except ImportError:
module = self._load_entry_point()
if module is not None:
return module
else:
raise
def _load_entry_point(self):
"""attempt to load this url's dialect from entry points, or return None
if pkg_resources is not installed or there is no matching entry point.
Raise ImportError if the actual load fails.
"""
try:
import pkg_resources
except ImportError:
return None
for res in pkg_resources.iter_entry_points('sqlalchemy.dialects'):
if res.name == self.drivername:
return res.load()
else:
return None
def translate_connect_args(self, names=[], **kw):
"""Translate url attributes into a dictionary of connection arguments.
r"""Translate url attributes into a dictionary of connection arguments.
Returns attributes of this url (`host`, `database`, `username`,
`password`, `port`) as a plain dictionary. The attribute names are
@@ -136,8 +165,8 @@ class URL(object):
:param \**kw: Optional, alternate key names for url attributes.
:param names: Deprecated. Same purpose as the keyword-based alternate names,
but correlates the name to the original positionally.
:param names: Deprecated. Same purpose as the keyword-based alternate
names, but correlates the name to the original positionally.
"""
translated = {}
@@ -153,6 +182,7 @@ class URL(object):
translated[name] = getattr(self, sname)
return translated
def make_url(name_or_url):
"""Given a string or unicode instance, produce a new URL instance.
@@ -160,25 +190,28 @@ def make_url(name_or_url):
existing URL object is passed, just returns the object.
"""
if isinstance(name_or_url, basestring):
if isinstance(name_or_url, util.string_types):
return _parse_rfc1738_args(name_or_url)
else:
return name_or_url
def _parse_rfc1738_args(name):
pattern = re.compile(r'''
(?P<name>[\w\+]+)://
(?:
(?P<username>[^:/]*)
(?::(?P<password>[^/]*))?
(?::(?P<password>.*))?
@)?
(?:
(?P<host>[^/:]*)
(?:
\[(?P<ipv6host>[^/]+)\] |
(?P<ipv4host>[^/:]+)
)?
(?::(?P<port>[^/]*))?
)?
(?:/(?P<database>.*))?
'''
, re.X)
''', re.X)
m = pattern.match(name)
if m is not None:
@@ -186,29 +219,43 @@ def _parse_rfc1738_args(name):
if components['database'] is not None:
tokens = components['database'].split('?', 2)
components['database'] = tokens[0]
query = (len(tokens) > 1 and dict(cgi.parse_qsl(tokens[1]))) or None
# Py2K
if query is not None:
query = (
len(tokens) > 1 and dict(util.parse_qsl(tokens[1]))) or None
if util.py2k and query is not None:
query = dict((k.encode('ascii'), query[k]) for k in query)
# end Py2K
else:
query = None
components['query'] = query
if components['password'] is not None:
components['password'] = urllib.unquote_plus(components['password'])
if components['username'] is not None:
components['username'] = _rfc_1738_unquote(components['username'])
if components['password'] is not None:
components['password'] = _rfc_1738_unquote(components['password'])
ipv4host = components.pop('ipv4host')
ipv6host = components.pop('ipv6host')
components['host'] = ipv4host or ipv6host
name = components.pop('name')
return URL(name, **components)
else:
raise exc.ArgumentError(
"Could not parse rfc1738 URL from string '%s'" % name)
def _rfc_1738_quote(text):
return re.sub(r'[:@/]', lambda m: "%%%X" % ord(m.group(0)), text)
def _rfc_1738_unquote(text):
return util.unquote(text)
def _parse_keyvalue_args(name):
m = re.match( r'(\w+)://(.*)', name)
m = re.match(r'(\w+)://(.*)', name)
if m is not None:
(name, args) = m.group(1, 2)
opts = dict( cgi.parse_qsl( args ) )
opts = dict(util.parse_qsl(args))
return URL(name, *opts)
else:
return None