1352 lines
48 KiB
Python
1352 lines
48 KiB
Python
# engine/default.py
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# Copyright (C) 2005-2018 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""Default implementations of per-dialect sqlalchemy.engine classes.
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These are semi-private implementation classes which are only of importance
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to database dialect authors; dialects will usually use the classes here
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as the base class for their own corresponding classes.
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"""
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import re
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import random
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from . import reflection, interfaces, result
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from ..sql import compiler, expression, schema
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from .. import types as sqltypes
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from .. import exc, util, pool, processors
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import codecs
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import weakref
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from .. import event
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AUTOCOMMIT_REGEXP = re.compile(
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r'\s*(?:UPDATE|INSERT|CREATE|DELETE|DROP|ALTER)',
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re.I | re.UNICODE)
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# When we're handed literal SQL, ensure it's a SELECT query
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SERVER_SIDE_CURSOR_RE = re.compile(
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r'\s*SELECT',
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re.I | re.UNICODE)
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class DefaultDialect(interfaces.Dialect):
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"""Default implementation of Dialect"""
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statement_compiler = compiler.SQLCompiler
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ddl_compiler = compiler.DDLCompiler
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type_compiler = compiler.GenericTypeCompiler
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preparer = compiler.IdentifierPreparer
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supports_alter = True
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supports_comments = False
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inline_comments = False
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# the first value we'd get for an autoincrement
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# column.
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default_sequence_base = 1
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# most DBAPIs happy with this for execute().
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# not cx_oracle.
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execute_sequence_format = tuple
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supports_views = True
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supports_sequences = False
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sequences_optional = False
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preexecute_autoincrement_sequences = False
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postfetch_lastrowid = True
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implicit_returning = False
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supports_right_nested_joins = True
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supports_native_enum = False
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supports_native_boolean = False
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supports_simple_order_by_label = True
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engine_config_types = util.immutabledict([
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('convert_unicode', util.bool_or_str('force')),
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('pool_timeout', util.asint),
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('echo', util.bool_or_str('debug')),
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('echo_pool', util.bool_or_str('debug')),
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('pool_recycle', util.asint),
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('pool_size', util.asint),
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('max_overflow', util.asint),
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('pool_threadlocal', util.asbool),
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])
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# if the NUMERIC type
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# returns decimal.Decimal.
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# *not* the FLOAT type however.
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supports_native_decimal = False
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if util.py3k:
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supports_unicode_statements = True
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supports_unicode_binds = True
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returns_unicode_strings = True
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description_encoding = None
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else:
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supports_unicode_statements = False
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supports_unicode_binds = False
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returns_unicode_strings = False
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description_encoding = 'use_encoding'
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name = 'default'
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# length at which to truncate
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# any identifier.
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max_identifier_length = 9999
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# length at which to truncate
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# the name of an index.
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# Usually None to indicate
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# 'use max_identifier_length'.
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# thanks to MySQL, sigh
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max_index_name_length = None
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supports_sane_rowcount = True
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supports_sane_multi_rowcount = True
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colspecs = {}
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default_paramstyle = 'named'
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supports_default_values = False
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supports_empty_insert = True
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supports_multivalues_insert = False
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supports_server_side_cursors = False
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server_version_info = None
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construct_arguments = None
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"""Optional set of argument specifiers for various SQLAlchemy
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constructs, typically schema items.
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To implement, establish as a series of tuples, as in::
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construct_arguments = [
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(schema.Index, {
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"using": False,
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"where": None,
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"ops": None
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})
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]
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If the above construct is established on the PostgreSQL dialect,
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the :class:`.Index` construct will now accept the keyword arguments
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``postgresql_using``, ``postgresql_where``, nad ``postgresql_ops``.
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Any other argument specified to the constructor of :class:`.Index`
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which is prefixed with ``postgresql_`` will raise :class:`.ArgumentError`.
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A dialect which does not include a ``construct_arguments`` member will
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not participate in the argument validation system. For such a dialect,
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any argument name is accepted by all participating constructs, within
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the namespace of arguments prefixed with that dialect name. The rationale
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here is so that third-party dialects that haven't yet implemented this
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feature continue to function in the old way.
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.. versionadded:: 0.9.2
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.. seealso::
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:class:`.DialectKWArgs` - implementing base class which consumes
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:attr:`.DefaultDialect.construct_arguments`
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"""
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# indicates symbol names are
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# UPPERCASEd if they are case insensitive
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# within the database.
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# if this is True, the methods normalize_name()
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# and denormalize_name() must be provided.
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requires_name_normalize = False
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reflection_options = ()
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dbapi_exception_translation_map = util.immutabledict()
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"""mapping used in the extremely unusual case that a DBAPI's
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published exceptions don't actually have the __name__ that they
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are linked towards.
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.. versionadded:: 1.0.5
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"""
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def __init__(self, convert_unicode=False,
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encoding='utf-8', paramstyle=None, dbapi=None,
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implicit_returning=None,
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supports_right_nested_joins=None,
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case_sensitive=True,
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supports_native_boolean=None,
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empty_in_strategy='static',
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label_length=None, **kwargs):
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if not getattr(self, 'ported_sqla_06', True):
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util.warn(
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"The %s dialect is not yet ported to the 0.6 format" %
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self.name)
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self.convert_unicode = convert_unicode
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self.encoding = encoding
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self.positional = False
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self._ischema = None
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self.dbapi = dbapi
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if paramstyle is not None:
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self.paramstyle = paramstyle
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elif self.dbapi is not None:
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self.paramstyle = self.dbapi.paramstyle
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else:
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self.paramstyle = self.default_paramstyle
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if implicit_returning is not None:
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self.implicit_returning = implicit_returning
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self.positional = self.paramstyle in ('qmark', 'format', 'numeric')
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self.identifier_preparer = self.preparer(self)
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self.type_compiler = self.type_compiler(self)
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if supports_right_nested_joins is not None:
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self.supports_right_nested_joins = supports_right_nested_joins
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if supports_native_boolean is not None:
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self.supports_native_boolean = supports_native_boolean
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self.case_sensitive = case_sensitive
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self.empty_in_strategy = empty_in_strategy
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if empty_in_strategy == 'static':
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self._use_static_in = True
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elif empty_in_strategy in ('dynamic', 'dynamic_warn'):
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self._use_static_in = False
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self._warn_on_empty_in = empty_in_strategy == 'dynamic_warn'
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else:
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raise exc.ArgumentError(
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"empty_in_strategy may be 'static', "
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"'dynamic', or 'dynamic_warn'")
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if label_length and label_length > self.max_identifier_length:
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raise exc.ArgumentError(
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"Label length of %d is greater than this dialect's"
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" maximum identifier length of %d" %
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(label_length, self.max_identifier_length))
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self.label_length = label_length
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if self.description_encoding == 'use_encoding':
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self._description_decoder = \
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processors.to_unicode_processor_factory(
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encoding
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)
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elif self.description_encoding is not None:
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self._description_decoder = \
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processors.to_unicode_processor_factory(
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self.description_encoding
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)
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self._encoder = codecs.getencoder(self.encoding)
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self._decoder = processors.to_unicode_processor_factory(self.encoding)
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@util.memoized_property
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def _type_memos(self):
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return weakref.WeakKeyDictionary()
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@property
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def dialect_description(self):
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return self.name + "+" + self.driver
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@property
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def supports_sane_rowcount_returning(self):
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return self.supports_sane_rowcount
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@classmethod
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def get_pool_class(cls, url):
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return getattr(cls, 'poolclass', pool.QueuePool)
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def initialize(self, connection):
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try:
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self.server_version_info = \
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self._get_server_version_info(connection)
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except NotImplementedError:
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self.server_version_info = None
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try:
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self.default_schema_name = \
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self._get_default_schema_name(connection)
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except NotImplementedError:
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self.default_schema_name = None
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try:
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self.default_isolation_level = \
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self.get_isolation_level(connection.connection)
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except NotImplementedError:
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self.default_isolation_level = None
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self.returns_unicode_strings = self._check_unicode_returns(connection)
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if self.description_encoding is not None and \
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self._check_unicode_description(connection):
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self._description_decoder = self.description_encoding = None
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self.do_rollback(connection.connection)
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def on_connect(self):
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"""return a callable which sets up a newly created DBAPI connection.
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This is used to set dialect-wide per-connection options such as
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isolation modes, unicode modes, etc.
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If a callable is returned, it will be assembled into a pool listener
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that receives the direct DBAPI connection, with all wrappers removed.
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If None is returned, no listener will be generated.
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"""
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return None
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def _check_unicode_returns(self, connection, additional_tests=None):
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if util.py2k and not self.supports_unicode_statements:
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cast_to = util.binary_type
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else:
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cast_to = util.text_type
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if self.positional:
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parameters = self.execute_sequence_format()
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else:
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parameters = {}
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def check_unicode(test):
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statement = cast_to(
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expression.select([test]).compile(dialect=self))
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try:
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cursor = connection.connection.cursor()
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connection._cursor_execute(cursor, statement, parameters)
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row = cursor.fetchone()
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cursor.close()
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except exc.DBAPIError as de:
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# note that _cursor_execute() will have closed the cursor
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# if an exception is thrown.
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util.warn("Exception attempting to "
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"detect unicode returns: %r" % de)
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return False
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else:
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return isinstance(row[0], util.text_type)
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tests = [
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# detect plain VARCHAR
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expression.cast(
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expression.literal_column("'test plain returns'"),
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sqltypes.VARCHAR(60)
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),
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# detect if there's an NVARCHAR type with different behavior
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# available
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expression.cast(
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expression.literal_column("'test unicode returns'"),
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sqltypes.Unicode(60)
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),
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]
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if additional_tests:
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tests += additional_tests
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results = {check_unicode(test) for test in tests}
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if results.issuperset([True, False]):
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return "conditional"
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else:
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return results == {True}
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def _check_unicode_description(self, connection):
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# all DBAPIs on Py2K return cursor.description as encoded,
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# until pypy2.1beta2 with sqlite, so let's just check it -
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# it's likely others will start doing this too in Py2k.
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if util.py2k and not self.supports_unicode_statements:
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cast_to = util.binary_type
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else:
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cast_to = util.text_type
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cursor = connection.connection.cursor()
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try:
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cursor.execute(
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cast_to(
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expression.select([
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expression.literal_column("'x'").label("some_label")
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]).compile(dialect=self)
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)
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)
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return isinstance(cursor.description[0][0], util.text_type)
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finally:
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cursor.close()
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def type_descriptor(self, typeobj):
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"""Provide a database-specific :class:`.TypeEngine` object, given
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the generic object which comes from the types module.
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This method looks for a dictionary called
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``colspecs`` as a class or instance-level variable,
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and passes on to :func:`.types.adapt_type`.
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"""
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return sqltypes.adapt_type(typeobj, self.colspecs)
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def reflecttable(
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self, connection, table, include_columns, exclude_columns, **opts):
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insp = reflection.Inspector.from_engine(connection)
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return insp.reflecttable(
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table, include_columns, exclude_columns, **opts)
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def get_pk_constraint(self, conn, table_name, schema=None, **kw):
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"""Compatibility method, adapts the result of get_primary_keys()
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for those dialects which don't implement get_pk_constraint().
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"""
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return {
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'constrained_columns':
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self.get_primary_keys(conn, table_name,
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schema=schema, **kw)
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}
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def validate_identifier(self, ident):
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if len(ident) > self.max_identifier_length:
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raise exc.IdentifierError(
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"Identifier '%s' exceeds maximum length of %d characters" %
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(ident, self.max_identifier_length)
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)
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def connect(self, *cargs, **cparams):
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return self.dbapi.connect(*cargs, **cparams)
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def create_connect_args(self, url):
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opts = url.translate_connect_args()
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opts.update(url.query)
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return [[], opts]
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def set_engine_execution_options(self, engine, opts):
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if 'isolation_level' in opts:
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isolation_level = opts['isolation_level']
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@event.listens_for(engine, "engine_connect")
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def set_isolation(connection, branch):
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if not branch:
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self._set_connection_isolation(connection, isolation_level)
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if 'schema_translate_map' in opts:
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getter = schema._schema_getter(opts['schema_translate_map'])
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engine.schema_for_object = getter
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@event.listens_for(engine, "engine_connect")
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def set_schema_translate_map(connection, branch):
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connection.schema_for_object = getter
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def set_connection_execution_options(self, connection, opts):
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if 'isolation_level' in opts:
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self._set_connection_isolation(connection, opts['isolation_level'])
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if 'schema_translate_map' in opts:
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getter = schema._schema_getter(opts['schema_translate_map'])
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connection.schema_for_object = getter
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def _set_connection_isolation(self, connection, level):
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if connection.in_transaction():
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util.warn(
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"Connection is already established with a Transaction; "
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"setting isolation_level may implicitly rollback or commit "
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"the existing transaction, or have no effect until "
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"next transaction")
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self.set_isolation_level(connection.connection, level)
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connection.connection._connection_record.\
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finalize_callback.append(self.reset_isolation_level)
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def do_begin(self, dbapi_connection):
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pass
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def do_rollback(self, dbapi_connection):
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dbapi_connection.rollback()
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def do_commit(self, dbapi_connection):
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dbapi_connection.commit()
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def do_close(self, dbapi_connection):
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dbapi_connection.close()
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@util.memoized_property
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def _dialect_specific_select_one(self):
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return str(expression.select([1]).compile(dialect=self))
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def do_ping(self, dbapi_connection):
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cursor = None
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try:
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cursor = dbapi_connection.cursor()
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try:
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cursor.execute(self._dialect_specific_select_one)
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finally:
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cursor.close()
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except self.dbapi.Error as err:
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if self.is_disconnect(err, dbapi_connection, cursor):
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return False
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else:
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raise
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else:
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return True
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def create_xid(self):
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"""Create a random two-phase transaction ID.
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This id will be passed to do_begin_twophase(), do_rollback_twophase(),
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do_commit_twophase(). Its format is unspecified.
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"""
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return "_sa_%032x" % random.randint(0, 2 ** 128)
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def do_savepoint(self, connection, name):
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connection.execute(expression.SavepointClause(name))
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def do_rollback_to_savepoint(self, connection, name):
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connection.execute(expression.RollbackToSavepointClause(name))
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def do_release_savepoint(self, connection, name):
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connection.execute(expression.ReleaseSavepointClause(name))
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def do_executemany(self, cursor, statement, parameters, context=None):
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cursor.executemany(statement, parameters)
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def do_execute(self, cursor, statement, parameters, context=None):
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cursor.execute(statement, parameters)
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def do_execute_no_params(self, cursor, statement, context=None):
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cursor.execute(statement)
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def is_disconnect(self, e, connection, cursor):
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return False
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def reset_isolation_level(self, dbapi_conn):
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# default_isolation_level is read from the first connection
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# after the initial set of 'isolation_level', if any, so is
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# the configured default of this dialect.
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self.set_isolation_level(dbapi_conn, self.default_isolation_level)
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class StrCompileDialect(DefaultDialect):
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statement_compiler = compiler.StrSQLCompiler
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ddl_compiler = compiler.DDLCompiler
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type_compiler = compiler.StrSQLTypeCompiler
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preparer = compiler.IdentifierPreparer
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|
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supports_sequences = True
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sequences_optional = True
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preexecute_autoincrement_sequences = False
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implicit_returning = False
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supports_native_boolean = True
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supports_simple_order_by_label = True
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class DefaultExecutionContext(interfaces.ExecutionContext):
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isinsert = False
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isupdate = False
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isdelete = False
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is_crud = False
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is_text = False
|
|
isddl = False
|
|
executemany = False
|
|
compiled = None
|
|
statement = None
|
|
result_column_struct = None
|
|
returned_defaults = None
|
|
_is_implicit_returning = False
|
|
_is_explicit_returning = False
|
|
|
|
# a hook for SQLite's translation of
|
|
# result column names
|
|
_translate_colname = None
|
|
|
|
_expanded_parameters = util.immutabledict()
|
|
|
|
@classmethod
|
|
def _init_ddl(cls, dialect, connection, dbapi_connection, compiled_ddl):
|
|
"""Initialize execution context for a DDLElement construct."""
|
|
|
|
self = cls.__new__(cls)
|
|
self.root_connection = connection
|
|
self._dbapi_connection = dbapi_connection
|
|
self.dialect = connection.dialect
|
|
|
|
self.compiled = compiled = compiled_ddl
|
|
self.isddl = True
|
|
|
|
self.execution_options = compiled.execution_options
|
|
if connection._execution_options:
|
|
self.execution_options = dict(self.execution_options)
|
|
self.execution_options.update(connection._execution_options)
|
|
|
|
if not dialect.supports_unicode_statements:
|
|
self.unicode_statement = util.text_type(compiled)
|
|
self.statement = dialect._encoder(self.unicode_statement)[0]
|
|
else:
|
|
self.statement = self.unicode_statement = util.text_type(compiled)
|
|
|
|
self.cursor = self.create_cursor()
|
|
self.compiled_parameters = []
|
|
|
|
if dialect.positional:
|
|
self.parameters = [dialect.execute_sequence_format()]
|
|
else:
|
|
self.parameters = [{}]
|
|
|
|
return self
|
|
|
|
@classmethod
|
|
def _init_compiled(cls, dialect, connection, dbapi_connection,
|
|
compiled, parameters):
|
|
"""Initialize execution context for a Compiled construct."""
|
|
|
|
self = cls.__new__(cls)
|
|
self.root_connection = connection
|
|
self._dbapi_connection = dbapi_connection
|
|
self.dialect = connection.dialect
|
|
|
|
self.compiled = compiled
|
|
|
|
# this should be caught in the engine before
|
|
# we get here
|
|
assert compiled.can_execute
|
|
|
|
self.execution_options = compiled.execution_options.union(
|
|
connection._execution_options)
|
|
|
|
self.result_column_struct = (
|
|
compiled._result_columns, compiled._ordered_columns,
|
|
compiled._textual_ordered_columns)
|
|
|
|
self.unicode_statement = util.text_type(compiled)
|
|
if not dialect.supports_unicode_statements:
|
|
self.statement = self.unicode_statement.encode(
|
|
self.dialect.encoding)
|
|
else:
|
|
self.statement = self.unicode_statement
|
|
|
|
self.isinsert = compiled.isinsert
|
|
self.isupdate = compiled.isupdate
|
|
self.isdelete = compiled.isdelete
|
|
self.is_text = compiled.isplaintext
|
|
|
|
if not parameters:
|
|
self.compiled_parameters = [compiled.construct_params()]
|
|
else:
|
|
self.compiled_parameters = \
|
|
[compiled.construct_params(m, _group_number=grp) for
|
|
grp, m in enumerate(parameters)]
|
|
|
|
self.executemany = len(parameters) > 1
|
|
|
|
self.cursor = self.create_cursor()
|
|
|
|
if self.isinsert or self.isupdate or self.isdelete:
|
|
self.is_crud = True
|
|
self._is_explicit_returning = bool(compiled.statement._returning)
|
|
self._is_implicit_returning = bool(
|
|
compiled.returning and not compiled.statement._returning)
|
|
|
|
if self.compiled.insert_prefetch or self.compiled.update_prefetch:
|
|
if self.executemany:
|
|
self._process_executemany_defaults()
|
|
else:
|
|
self._process_executesingle_defaults()
|
|
|
|
processors = compiled._bind_processors
|
|
|
|
if compiled.contains_expanding_parameters:
|
|
positiontup = self._expand_in_parameters(compiled, processors)
|
|
elif compiled.positional:
|
|
positiontup = self.compiled.positiontup
|
|
|
|
# Convert the dictionary of bind parameter values
|
|
# into a dict or list to be sent to the DBAPI's
|
|
# execute() or executemany() method.
|
|
parameters = []
|
|
if compiled.positional:
|
|
for compiled_params in self.compiled_parameters:
|
|
param = []
|
|
for key in positiontup:
|
|
if key in processors:
|
|
param.append(processors[key](compiled_params[key]))
|
|
else:
|
|
param.append(compiled_params[key])
|
|
parameters.append(dialect.execute_sequence_format(param))
|
|
else:
|
|
encode = not dialect.supports_unicode_statements
|
|
for compiled_params in self.compiled_parameters:
|
|
|
|
if encode:
|
|
param = dict(
|
|
(
|
|
dialect._encoder(key)[0],
|
|
processors[key](compiled_params[key])
|
|
if key in processors
|
|
else compiled_params[key]
|
|
)
|
|
for key in compiled_params
|
|
)
|
|
else:
|
|
param = dict(
|
|
(
|
|
key,
|
|
processors[key](compiled_params[key])
|
|
if key in processors
|
|
else compiled_params[key]
|
|
)
|
|
for key in compiled_params
|
|
)
|
|
|
|
parameters.append(param)
|
|
|
|
self.parameters = dialect.execute_sequence_format(parameters)
|
|
|
|
return self
|
|
|
|
def _expand_in_parameters(self, compiled, processors):
|
|
"""handle special 'expanding' parameters, IN tuples that are rendered
|
|
on a per-parameter basis for an otherwise fixed SQL statement string.
|
|
|
|
"""
|
|
if self.executemany:
|
|
raise exc.InvalidRequestError(
|
|
"'expanding' parameters can't be used with "
|
|
"executemany()")
|
|
|
|
if self.compiled.positional and self.compiled._numeric_binds:
|
|
# I'm not familiar with any DBAPI that uses 'numeric'
|
|
raise NotImplementedError(
|
|
"'expanding' bind parameters not supported with "
|
|
"'numeric' paramstyle at this time.")
|
|
|
|
self._expanded_parameters = {}
|
|
|
|
compiled_params = self.compiled_parameters[0]
|
|
if compiled.positional:
|
|
positiontup = []
|
|
else:
|
|
positiontup = None
|
|
|
|
replacement_expressions = {}
|
|
for name in (
|
|
self.compiled.positiontup if compiled.positional
|
|
else self.compiled.binds
|
|
):
|
|
parameter = self.compiled.binds[name]
|
|
if parameter.expanding:
|
|
values = compiled_params.pop(name)
|
|
if not values:
|
|
raise exc.InvalidRequestError(
|
|
"'expanding' parameters can't be used with an "
|
|
"empty list"
|
|
)
|
|
elif isinstance(values[0], (tuple, list)):
|
|
to_update = [
|
|
("%s_%s_%s" % (name, i, j), value)
|
|
for i, tuple_element in enumerate(values, 1)
|
|
for j, value in enumerate(tuple_element, 1)
|
|
]
|
|
replacement_expressions[name] = ", ".join(
|
|
"(%s)" % ", ".join(
|
|
self.compiled.bindtemplate % {
|
|
"name":
|
|
to_update[i * len(tuple_element) + j][0]
|
|
}
|
|
for j, value in enumerate(tuple_element)
|
|
)
|
|
for i, tuple_element in enumerate(values)
|
|
|
|
)
|
|
else:
|
|
to_update = [
|
|
("%s_%s" % (name, i), value)
|
|
for i, value in enumerate(values, 1)
|
|
]
|
|
replacement_expressions[name] = ", ".join(
|
|
self.compiled.bindtemplate % {
|
|
"name": key}
|
|
for key, value in to_update
|
|
)
|
|
compiled_params.update(to_update)
|
|
processors.update(
|
|
(key, processors[name])
|
|
for key, value in to_update if name in processors
|
|
)
|
|
if compiled.positional:
|
|
positiontup.extend(name for name, value in to_update)
|
|
self._expanded_parameters[name] = [
|
|
expand_key for expand_key, value in to_update]
|
|
elif compiled.positional:
|
|
positiontup.append(name)
|
|
|
|
def process_expanding(m):
|
|
return replacement_expressions.pop(m.group(1))
|
|
|
|
self.statement = re.sub(
|
|
r"\[EXPANDING_(\S+)\]",
|
|
process_expanding,
|
|
self.statement
|
|
)
|
|
return positiontup
|
|
|
|
@classmethod
|
|
def _init_statement(cls, dialect, connection, dbapi_connection,
|
|
statement, parameters):
|
|
"""Initialize execution context for a string SQL statement."""
|
|
|
|
self = cls.__new__(cls)
|
|
self.root_connection = connection
|
|
self._dbapi_connection = dbapi_connection
|
|
self.dialect = connection.dialect
|
|
self.is_text = True
|
|
|
|
# plain text statement
|
|
self.execution_options = connection._execution_options
|
|
|
|
if not parameters:
|
|
if self.dialect.positional:
|
|
self.parameters = [dialect.execute_sequence_format()]
|
|
else:
|
|
self.parameters = [{}]
|
|
elif isinstance(parameters[0], dialect.execute_sequence_format):
|
|
self.parameters = parameters
|
|
elif isinstance(parameters[0], dict):
|
|
if dialect.supports_unicode_statements:
|
|
self.parameters = parameters
|
|
else:
|
|
self.parameters = [
|
|
{dialect._encoder(k)[0]: d[k] for k in d}
|
|
for d in parameters
|
|
] or [{}]
|
|
else:
|
|
self.parameters = [dialect.execute_sequence_format(p)
|
|
for p in parameters]
|
|
|
|
self.executemany = len(parameters) > 1
|
|
|
|
if not dialect.supports_unicode_statements and \
|
|
isinstance(statement, util.text_type):
|
|
self.unicode_statement = statement
|
|
self.statement = dialect._encoder(statement)[0]
|
|
else:
|
|
self.statement = self.unicode_statement = statement
|
|
|
|
self.cursor = self.create_cursor()
|
|
return self
|
|
|
|
@classmethod
|
|
def _init_default(cls, dialect, connection, dbapi_connection):
|
|
"""Initialize execution context for a ColumnDefault construct."""
|
|
|
|
self = cls.__new__(cls)
|
|
self.root_connection = connection
|
|
self._dbapi_connection = dbapi_connection
|
|
self.dialect = connection.dialect
|
|
self.execution_options = connection._execution_options
|
|
self.cursor = self.create_cursor()
|
|
return self
|
|
|
|
@util.memoized_property
|
|
def engine(self):
|
|
return self.root_connection.engine
|
|
|
|
@util.memoized_property
|
|
def postfetch_cols(self):
|
|
return self.compiled.postfetch
|
|
|
|
@util.memoized_property
|
|
def prefetch_cols(self):
|
|
if self.isinsert:
|
|
return self.compiled.insert_prefetch
|
|
elif self.isupdate:
|
|
return self.compiled.update_prefetch
|
|
else:
|
|
return ()
|
|
|
|
@util.memoized_property
|
|
def returning_cols(self):
|
|
self.compiled.returning
|
|
|
|
@util.memoized_property
|
|
def no_parameters(self):
|
|
return self.execution_options.get("no_parameters", False)
|
|
|
|
@util.memoized_property
|
|
def should_autocommit(self):
|
|
autocommit = self.execution_options.get('autocommit',
|
|
not self.compiled and
|
|
self.statement and
|
|
expression.PARSE_AUTOCOMMIT
|
|
or False)
|
|
|
|
if autocommit is expression.PARSE_AUTOCOMMIT:
|
|
return self.should_autocommit_text(self.unicode_statement)
|
|
else:
|
|
return autocommit
|
|
|
|
def _execute_scalar(self, stmt, type_):
|
|
"""Execute a string statement on the current cursor, returning a
|
|
scalar result.
|
|
|
|
Used to fire off sequences, default phrases, and "select lastrowid"
|
|
types of statements individually or in the context of a parent INSERT
|
|
or UPDATE statement.
|
|
|
|
"""
|
|
|
|
conn = self.root_connection
|
|
if isinstance(stmt, util.text_type) and \
|
|
not self.dialect.supports_unicode_statements:
|
|
stmt = self.dialect._encoder(stmt)[0]
|
|
|
|
if self.dialect.positional:
|
|
default_params = self.dialect.execute_sequence_format()
|
|
else:
|
|
default_params = {}
|
|
|
|
conn._cursor_execute(self.cursor, stmt, default_params, context=self)
|
|
r = self.cursor.fetchone()[0]
|
|
if type_ is not None:
|
|
# apply type post processors to the result
|
|
proc = type_._cached_result_processor(
|
|
self.dialect,
|
|
self.cursor.description[0][1]
|
|
)
|
|
if proc:
|
|
return proc(r)
|
|
return r
|
|
|
|
@property
|
|
def connection(self):
|
|
return self.root_connection._branch()
|
|
|
|
def should_autocommit_text(self, statement):
|
|
return AUTOCOMMIT_REGEXP.match(statement)
|
|
|
|
def _use_server_side_cursor(self):
|
|
if not self.dialect.supports_server_side_cursors:
|
|
return False
|
|
|
|
if self.dialect.server_side_cursors:
|
|
use_server_side = \
|
|
self.execution_options.get('stream_results', True) and (
|
|
(self.compiled and isinstance(self.compiled.statement,
|
|
expression.Selectable)
|
|
or
|
|
(
|
|
(not self.compiled or
|
|
isinstance(self.compiled.statement,
|
|
expression.TextClause))
|
|
and self.statement and SERVER_SIDE_CURSOR_RE.match(
|
|
self.statement))
|
|
)
|
|
)
|
|
else:
|
|
use_server_side = \
|
|
self.execution_options.get('stream_results', False)
|
|
|
|
return use_server_side
|
|
|
|
def create_cursor(self):
|
|
if self._use_server_side_cursor():
|
|
self._is_server_side = True
|
|
return self.create_server_side_cursor()
|
|
else:
|
|
self._is_server_side = False
|
|
return self._dbapi_connection.cursor()
|
|
|
|
def create_server_side_cursor(self):
|
|
raise NotImplementedError()
|
|
|
|
def pre_exec(self):
|
|
pass
|
|
|
|
def post_exec(self):
|
|
pass
|
|
|
|
def get_result_processor(self, type_, colname, coltype):
|
|
"""Return a 'result processor' for a given type as present in
|
|
cursor.description.
|
|
|
|
This has a default implementation that dialects can override
|
|
for context-sensitive result type handling.
|
|
|
|
"""
|
|
return type_._cached_result_processor(self.dialect, coltype)
|
|
|
|
def get_lastrowid(self):
|
|
"""return self.cursor.lastrowid, or equivalent, after an INSERT.
|
|
|
|
This may involve calling special cursor functions,
|
|
issuing a new SELECT on the cursor (or a new one),
|
|
or returning a stored value that was
|
|
calculated within post_exec().
|
|
|
|
This function will only be called for dialects
|
|
which support "implicit" primary key generation,
|
|
keep preexecute_autoincrement_sequences set to False,
|
|
and when no explicit id value was bound to the
|
|
statement.
|
|
|
|
The function is called once, directly after
|
|
post_exec() and before the transaction is committed
|
|
or ResultProxy is generated. If the post_exec()
|
|
method assigns a value to `self._lastrowid`, the
|
|
value is used in place of calling get_lastrowid().
|
|
|
|
Note that this method is *not* equivalent to the
|
|
``lastrowid`` method on ``ResultProxy``, which is a
|
|
direct proxy to the DBAPI ``lastrowid`` accessor
|
|
in all cases.
|
|
|
|
"""
|
|
return self.cursor.lastrowid
|
|
|
|
def handle_dbapi_exception(self, e):
|
|
pass
|
|
|
|
def get_result_proxy(self):
|
|
if self._is_server_side:
|
|
return result.BufferedRowResultProxy(self)
|
|
else:
|
|
return result.ResultProxy(self)
|
|
|
|
@property
|
|
def rowcount(self):
|
|
return self.cursor.rowcount
|
|
|
|
def supports_sane_rowcount(self):
|
|
return self.dialect.supports_sane_rowcount
|
|
|
|
def supports_sane_multi_rowcount(self):
|
|
return self.dialect.supports_sane_multi_rowcount
|
|
|
|
def _setup_crud_result_proxy(self):
|
|
if self.isinsert and \
|
|
not self.executemany:
|
|
if not self._is_implicit_returning and \
|
|
not self.compiled.inline and \
|
|
self.dialect.postfetch_lastrowid:
|
|
|
|
self._setup_ins_pk_from_lastrowid()
|
|
|
|
elif not self._is_implicit_returning:
|
|
self._setup_ins_pk_from_empty()
|
|
|
|
result = self.get_result_proxy()
|
|
|
|
if self.isinsert:
|
|
if self._is_implicit_returning:
|
|
row = result.fetchone()
|
|
self.returned_defaults = row
|
|
self._setup_ins_pk_from_implicit_returning(row)
|
|
result._soft_close()
|
|
result._metadata = None
|
|
elif not self._is_explicit_returning:
|
|
result._soft_close()
|
|
result._metadata = None
|
|
elif self.isupdate and self._is_implicit_returning:
|
|
row = result.fetchone()
|
|
self.returned_defaults = row
|
|
result._soft_close()
|
|
result._metadata = None
|
|
|
|
elif result._metadata is None:
|
|
# no results, get rowcount
|
|
# (which requires open cursor on some drivers
|
|
# such as kintersbasdb, mxodbc)
|
|
result.rowcount
|
|
result._soft_close()
|
|
return result
|
|
|
|
def _setup_ins_pk_from_lastrowid(self):
|
|
key_getter = self.compiled._key_getters_for_crud_column[2]
|
|
table = self.compiled.statement.table
|
|
compiled_params = self.compiled_parameters[0]
|
|
|
|
lastrowid = self.get_lastrowid()
|
|
if lastrowid is not None:
|
|
autoinc_col = table._autoincrement_column
|
|
if autoinc_col is not None:
|
|
# apply type post processors to the lastrowid
|
|
proc = autoinc_col.type._cached_result_processor(
|
|
self.dialect, None)
|
|
if proc is not None:
|
|
lastrowid = proc(lastrowid)
|
|
self.inserted_primary_key = [
|
|
lastrowid if c is autoinc_col else
|
|
compiled_params.get(key_getter(c), None)
|
|
for c in table.primary_key
|
|
]
|
|
else:
|
|
# don't have a usable lastrowid, so
|
|
# do the same as _setup_ins_pk_from_empty
|
|
self.inserted_primary_key = [
|
|
compiled_params.get(key_getter(c), None)
|
|
for c in table.primary_key
|
|
]
|
|
|
|
def _setup_ins_pk_from_empty(self):
|
|
key_getter = self.compiled._key_getters_for_crud_column[2]
|
|
table = self.compiled.statement.table
|
|
compiled_params = self.compiled_parameters[0]
|
|
self.inserted_primary_key = [
|
|
compiled_params.get(key_getter(c), None)
|
|
for c in table.primary_key
|
|
]
|
|
|
|
def _setup_ins_pk_from_implicit_returning(self, row):
|
|
if row is None:
|
|
self.inserted_primary_key = None
|
|
return
|
|
|
|
key_getter = self.compiled._key_getters_for_crud_column[2]
|
|
table = self.compiled.statement.table
|
|
compiled_params = self.compiled_parameters[0]
|
|
self.inserted_primary_key = [
|
|
row[col] if value is None else value
|
|
for col, value in [
|
|
(col, compiled_params.get(key_getter(col), None))
|
|
for col in table.primary_key
|
|
]
|
|
]
|
|
|
|
def lastrow_has_defaults(self):
|
|
return (self.isinsert or self.isupdate) and \
|
|
bool(self.compiled.postfetch)
|
|
|
|
def set_input_sizes(
|
|
self, translate=None, include_types=None, exclude_types=None):
|
|
"""Given a cursor and ClauseParameters, call the appropriate
|
|
style of ``setinputsizes()`` on the cursor, using DB-API types
|
|
from the bind parameter's ``TypeEngine`` objects.
|
|
|
|
This method only called by those dialects which require it,
|
|
currently cx_oracle.
|
|
|
|
"""
|
|
|
|
if not hasattr(self.compiled, 'bind_names'):
|
|
return
|
|
|
|
types = dict(
|
|
(self.compiled.bind_names[bindparam], bindparam.type)
|
|
for bindparam in self.compiled.bind_names)
|
|
|
|
if self.dialect.positional:
|
|
inputsizes = []
|
|
for key in self.compiled.positiontup:
|
|
typeengine = types[key]
|
|
dbtype = typeengine.dialect_impl(self.dialect).\
|
|
get_dbapi_type(self.dialect.dbapi)
|
|
if dbtype is not None and \
|
|
(not exclude_types or dbtype not in exclude_types) and \
|
|
(not include_types or dbtype in include_types):
|
|
if key in self._expanded_parameters:
|
|
inputsizes.extend(
|
|
[dbtype] * len(self._expanded_parameters[key]))
|
|
else:
|
|
inputsizes.append(dbtype)
|
|
try:
|
|
self.cursor.setinputsizes(*inputsizes)
|
|
except BaseException as e:
|
|
self.root_connection._handle_dbapi_exception(
|
|
e, None, None, None, self)
|
|
else:
|
|
inputsizes = {}
|
|
for key in self.compiled.bind_names.values():
|
|
typeengine = types[key]
|
|
dbtype = typeengine.dialect_impl(self.dialect).\
|
|
get_dbapi_type(self.dialect.dbapi)
|
|
if dbtype is not None and \
|
|
(not exclude_types or dbtype not in exclude_types) and \
|
|
(not include_types or dbtype in include_types):
|
|
if translate:
|
|
# TODO: this part won't work w/ the
|
|
# expanded_parameters feature, e.g. for cx_oracle
|
|
# quoted bound names
|
|
key = translate.get(key, key)
|
|
if not self.dialect.supports_unicode_binds:
|
|
key = self.dialect._encoder(key)[0]
|
|
if key in self._expanded_parameters:
|
|
inputsizes.update(
|
|
(expand_key, dbtype) for expand_key
|
|
in self._expanded_parameters[key]
|
|
)
|
|
else:
|
|
inputsizes[key] = dbtype
|
|
try:
|
|
self.cursor.setinputsizes(**inputsizes)
|
|
except BaseException as e:
|
|
self.root_connection._handle_dbapi_exception(
|
|
e, None, None, None, self)
|
|
|
|
def _exec_default(self, column, default, type_):
|
|
if default.is_sequence:
|
|
return self.fire_sequence(default, type_)
|
|
elif default.is_callable:
|
|
self.current_column = column
|
|
return default.arg(self)
|
|
elif default.is_clause_element:
|
|
# TODO: expensive branching here should be
|
|
# pulled into _exec_scalar()
|
|
conn = self.connection
|
|
if not default._arg_is_typed:
|
|
default_arg = expression.type_coerce(default.arg, type_)
|
|
else:
|
|
default_arg = default.arg
|
|
c = expression.select([default_arg]).compile(bind=conn)
|
|
return conn._execute_compiled(c, (), {}).scalar()
|
|
else:
|
|
return default.arg
|
|
|
|
current_parameters = None
|
|
"""A dictionary of parameters applied to the current row.
|
|
|
|
This attribute is only available in the context of a user-defined default
|
|
generation function, e.g. as described at :ref:`context_default_functions`.
|
|
It consists of a dictionary which includes entries for each column/value
|
|
pair that is to be part of the INSERT or UPDATE statement. The keys of the
|
|
dictionary will be the key value of each :class:`.Column`, which is usually
|
|
synonymous with the name.
|
|
|
|
Note that the :attr:`.DefaultExecutionContext.current_parameters` attribute
|
|
does not accommodate for the "multi-values" feature of the
|
|
:meth:`.Insert.values` method. The
|
|
:meth:`.DefaultExecutionContext.get_current_parameters` method should be
|
|
preferred.
|
|
|
|
.. seealso::
|
|
|
|
:meth:`.DefaultExecutionContext.get_current_parameters`
|
|
|
|
:ref:`context_default_functions`
|
|
|
|
"""
|
|
|
|
def get_current_parameters(self, isolate_multiinsert_groups=True):
|
|
"""Return a dictionary of parameters applied to the current row.
|
|
|
|
This method can only be used in the context of a user-defined default
|
|
generation function, e.g. as described at
|
|
:ref:`context_default_functions`. When invoked, a dictionary is
|
|
returned which includes entries for each column/value pair that is part
|
|
of the INSERT or UPDATE statement. The keys of the dictionary will be
|
|
the key value of each :class:`.Column`, which is usually synonymous
|
|
with the name.
|
|
|
|
:param isolate_multiinsert_groups=True: indicates that multi-valued
|
|
INSERT contructs created using :meth:`.Insert.values` should be
|
|
handled by returning only the subset of parameters that are local
|
|
to the current column default invocation. When ``False``, the
|
|
raw parameters of the statement are returned including the
|
|
naming convention used in the case of multi-valued INSERT.
|
|
|
|
.. versionadded:: 1.2 added
|
|
:meth:`.DefaultExecutionContext.get_current_parameters`
|
|
which provides more functionality over the existing
|
|
:attr:`.DefaultExecutionContext.current_parameters`
|
|
attribute.
|
|
|
|
.. seealso::
|
|
|
|
:attr:`.DefaultExecutionContext.current_parameters`
|
|
|
|
:ref:`context_default_functions`
|
|
|
|
"""
|
|
try:
|
|
parameters = self.current_parameters
|
|
column = self.current_column
|
|
except AttributeError:
|
|
raise exc.InvalidRequestError(
|
|
"get_current_parameters() can only be invoked in the "
|
|
"context of a Python side column default function")
|
|
if isolate_multiinsert_groups and \
|
|
self.isinsert and \
|
|
self.compiled.statement._has_multi_parameters:
|
|
if column._is_multiparam_column:
|
|
index = column.index + 1
|
|
d = {column.original.key: parameters[column.key]}
|
|
else:
|
|
d = {column.key: parameters[column.key]}
|
|
index = 0
|
|
keys = self.compiled.statement.parameters[0].keys()
|
|
d.update(
|
|
(key, parameters["%s_m%d" % (key, index)])
|
|
for key in keys
|
|
)
|
|
return d
|
|
else:
|
|
return parameters
|
|
|
|
def get_insert_default(self, column):
|
|
if column.default is None:
|
|
return None
|
|
else:
|
|
return self._exec_default(column, column.default, column.type)
|
|
|
|
def get_update_default(self, column):
|
|
if column.onupdate is None:
|
|
return None
|
|
else:
|
|
return self._exec_default(column, column.onupdate, column.type)
|
|
|
|
def _process_executemany_defaults(self):
|
|
key_getter = self.compiled._key_getters_for_crud_column[2]
|
|
|
|
scalar_defaults = {}
|
|
|
|
insert_prefetch = self.compiled.insert_prefetch
|
|
update_prefetch = self.compiled.update_prefetch
|
|
|
|
# pre-determine scalar Python-side defaults
|
|
# to avoid many calls of get_insert_default()/
|
|
# get_update_default()
|
|
for c in insert_prefetch:
|
|
if c.default and c.default.is_scalar:
|
|
scalar_defaults[c] = c.default.arg
|
|
for c in update_prefetch:
|
|
if c.onupdate and c.onupdate.is_scalar:
|
|
scalar_defaults[c] = c.onupdate.arg
|
|
|
|
for param in self.compiled_parameters:
|
|
self.current_parameters = param
|
|
for c in insert_prefetch:
|
|
if c in scalar_defaults:
|
|
val = scalar_defaults[c]
|
|
else:
|
|
val = self.get_insert_default(c)
|
|
if val is not None:
|
|
param[key_getter(c)] = val
|
|
for c in update_prefetch:
|
|
if c in scalar_defaults:
|
|
val = scalar_defaults[c]
|
|
else:
|
|
val = self.get_update_default(c)
|
|
if val is not None:
|
|
param[key_getter(c)] = val
|
|
|
|
del self.current_parameters
|
|
|
|
def _process_executesingle_defaults(self):
|
|
key_getter = self.compiled._key_getters_for_crud_column[2]
|
|
self.current_parameters = compiled_parameters = \
|
|
self.compiled_parameters[0]
|
|
|
|
for c in self.compiled.insert_prefetch:
|
|
if c.default and \
|
|
not c.default.is_sequence and c.default.is_scalar:
|
|
val = c.default.arg
|
|
else:
|
|
val = self.get_insert_default(c)
|
|
|
|
if val is not None:
|
|
compiled_parameters[key_getter(c)] = val
|
|
|
|
for c in self.compiled.update_prefetch:
|
|
val = self.get_update_default(c)
|
|
|
|
if val is not None:
|
|
compiled_parameters[key_getter(c)] = val
|
|
del self.current_parameters
|
|
|
|
|
|
DefaultDialect.execution_ctx_cls = DefaultExecutionContext
|