You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
119 lines
3.5 KiB
119 lines
3.5 KiB
3 years ago
|
# engine/mock.py
|
||
|
|
# Copyright (C) 2005-2022 the SQLAlchemy authors and contributors
|
||
|
|
# <see AUTHORS file>
|
||
|
|
#
|
||
|
|
# This module is part of SQLAlchemy and is released under
|
||
|
|
# the MIT License: https://www.opensource.org/licenses/mit-license.php
|
||
|
|
|
||
|
|
from operator import attrgetter
|
||
|
|
|
||
|
|
from . import base
|
||
|
|
from . import url as _url
|
||
|
|
from .. import util
|
||
|
|
from ..sql import ddl
|
||
|
|
|
||
|
|
|
||
|
|
class MockConnection(base.Connectable):
|
||
|
|
def __init__(self, dialect, execute):
|
||
|
|
self._dialect = dialect
|
||
|
|
self.execute = execute
|
||
|
|
|
||
|
|
engine = property(lambda s: s)
|
||
|
|
dialect = property(attrgetter("_dialect"))
|
||
|
|
name = property(lambda s: s._dialect.name)
|
||
|
|
|
||
|
|
def schema_for_object(self, obj):
|
||
|
|
return obj.schema
|
||
|
|
|
||
|
|
def 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
|
||
|
|
)
|
||
|
|
|
||
|
|
def create(self, entity, **kwargs):
|
||
|
|
kwargs["checkfirst"] = False
|
||
|
|
|
||
|
|
ddl.SchemaGenerator(self.dialect, self, **kwargs).traverse_single(
|
||
|
|
entity
|
||
|
|
)
|
||
|
|
|
||
|
|
def drop(self, entity, **kwargs):
|
||
|
|
kwargs["checkfirst"] = False
|
||
|
|
|
||
|
|
ddl.SchemaDropper(self.dialect, self, **kwargs).traverse_single(entity)
|
||
|
|
|
||
|
|
def _run_ddl_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()
|
||
|
|
|
||
|
|
|
||
|
|
def create_mock_engine(url, executor, **kw):
|
||
|
|
"""Create a "mock" engine used for echoing DDL.
|
||
|
|
|
||
|
|
This is a utility function used for debugging or storing the output of DDL
|
||
|
|
sequences as generated by :meth:`_schema.MetaData.create_all`
|
||
|
|
and related methods.
|
||
|
|
|
||
|
|
The function accepts a URL which is used only to determine the kind of
|
||
|
|
dialect to be used, as well as an "executor" callable function which
|
||
|
|
will receive a SQL expression object and parameters, which can then be
|
||
|
|
echoed or otherwise printed. The executor's return value is not handled,
|
||
|
|
nor does the engine allow regular string statements to be invoked, and
|
||
|
|
is therefore only useful for DDL that is sent to the database without
|
||
|
|
receiving any results.
|
||
|
|
|
||
|
|
E.g.::
|
||
|
|
|
||
|
|
from sqlalchemy import create_mock_engine
|
||
|
|
|
||
|
|
def dump(sql, *multiparams, **params):
|
||
|
|
print(sql.compile(dialect=engine.dialect))
|
||
|
|
|
||
|
|
engine = create_mock_engine('postgresql://', dump)
|
||
|
|
metadata.create_all(engine, checkfirst=False)
|
||
|
|
|
||
|
|
:param url: A string URL which typically needs to contain only the
|
||
|
|
database backend name.
|
||
|
|
|
||
|
|
:param executor: a callable which receives the arguments ``sql``,
|
||
|
|
``*multiparams`` and ``**params``. The ``sql`` parameter is typically
|
||
|
|
an instance of :class:`.DDLElement`, which can then be compiled into a
|
||
|
|
string using :meth:`.DDLElement.compile`.
|
||
|
|
|
||
|
|
.. versionadded:: 1.4 - the :func:`.create_mock_engine` function replaces
|
||
|
|
the previous "mock" engine strategy used with
|
||
|
|
:func:`_sa.create_engine`.
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
:ref:`faq_ddl_as_string`
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
# create url.URL object
|
||
|
|
u = _url.make_url(url)
|
||
|
|
|
||
|
|
dialect_cls = u.get_dialect()
|
||
|
|
|
||
|
|
dialect_args = {}
|
||
|
|
# consume dialect arguments from kwargs
|
||
|
|
for k in util.get_cls_kwargs(dialect_cls):
|
||
|
|
if k in kw:
|
||
|
|
dialect_args[k] = kw.pop(k)
|
||
|
|
|
||
|
|
# create dialect
|
||
|
|
dialect = dialect_cls(**dialect_args)
|
||
|
|
|
||
|
|
return MockConnection(dialect, executor)
|