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bazarr/libs/sqlalchemy/engine/default.py

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72 KiB

# engine/default.py
# Copyright (C) 2005-2023 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
# mypy: allow-untyped-defs, allow-untyped-calls
"""Default implementations of per-dialect sqlalchemy.engine classes.
These are semi-private implementation classes which are only of importance
to database dialect authors; dialects will usually use the classes here
as the base class for their own corresponding classes.
"""
from __future__ import annotations
import functools
import random
import re
from time import perf_counter
import typing
from typing import Any
from typing import Callable
from typing import cast
from typing import Dict
from typing import List
from typing import Mapping
from typing import MutableMapping
from typing import MutableSequence
from typing import Optional
from typing import Sequence
from typing import Set
from typing import Tuple
from typing import Type
from typing import TYPE_CHECKING
from typing import Union
import weakref
from . import characteristics
from . import cursor as _cursor
from . import interfaces
from .base import Connection
from .interfaces import CacheStats
from .interfaces import DBAPICursor
from .interfaces import Dialect
from .interfaces import ExecuteStyle
from .interfaces import ExecutionContext
from .reflection import ObjectKind
from .reflection import ObjectScope
from .. import event
from .. import exc
from .. import pool
from .. import util
from ..sql import compiler
from ..sql import dml
from ..sql import expression
from ..sql import type_api
from ..sql._typing import is_tuple_type
from ..sql.base import _NoArg
from ..sql.compiler import DDLCompiler
from ..sql.compiler import SQLCompiler
from ..sql.elements import quoted_name
from ..sql.schema import default_is_scalar
from ..util.typing import Final
from ..util.typing import Literal
if typing.TYPE_CHECKING:
from types import ModuleType
from .base import Engine
from .interfaces import _CoreMultiExecuteParams
from .interfaces import _CoreSingleExecuteParams
from .interfaces import _DBAPICursorDescription
from .interfaces import _DBAPIMultiExecuteParams
from .interfaces import _ExecuteOptions
from .interfaces import _MutableCoreSingleExecuteParams
from .interfaces import _ParamStyle
from .interfaces import DBAPIConnection
from .interfaces import IsolationLevel
from .row import Row
from .url import URL
from ..event import _ListenerFnType
from ..pool import Pool
from ..pool import PoolProxiedConnection
from ..sql import Executable
from ..sql.compiler import Compiled
from ..sql.compiler import Linting
from ..sql.compiler import ResultColumnsEntry
from ..sql.dml import DMLState
from ..sql.dml import UpdateBase
from ..sql.elements import BindParameter
from ..sql.schema import Column
from ..sql.type_api import _BindProcessorType
from ..sql.type_api import TypeEngine
# When we're handed literal SQL, ensure it's a SELECT query
SERVER_SIDE_CURSOR_RE = re.compile(r"\s*SELECT", re.I | re.UNICODE)
(
CACHE_HIT,
CACHE_MISS,
CACHING_DISABLED,
NO_CACHE_KEY,
NO_DIALECT_SUPPORT,
) = list(CacheStats)
class DefaultDialect(Dialect):
"""Default implementation of Dialect"""
statement_compiler = compiler.SQLCompiler
ddl_compiler = compiler.DDLCompiler
type_compiler_cls = compiler.GenericTypeCompiler
preparer = compiler.IdentifierPreparer
supports_alter = True
supports_comments = False
supports_constraint_comments = False
inline_comments = False
supports_statement_cache = True
div_is_floordiv = True
bind_typing = interfaces.BindTyping.NONE
include_set_input_sizes: Optional[Set[Any]] = None
exclude_set_input_sizes: Optional[Set[Any]] = None
# the first value we'd get for an autoincrement column.
default_sequence_base = 1
# most DBAPIs happy with this for execute().
# not cx_oracle.
execute_sequence_format = tuple # type: ignore
supports_schemas = True
supports_views = True
supports_sequences = False
sequences_optional = False
preexecute_autoincrement_sequences = False
supports_identity_columns = False
postfetch_lastrowid = True
favor_returning_over_lastrowid = False
insert_null_pk_still_autoincrements = False
update_returning = False
delete_returning = False
update_returning_multifrom = False
delete_returning_multifrom = False
insert_returning = False
cte_follows_insert = False
supports_native_enum = False
supports_native_boolean = False
supports_native_uuid = False
non_native_boolean_check_constraint = True
supports_simple_order_by_label = True
tuple_in_values = False
connection_characteristics = util.immutabledict(
{"isolation_level": characteristics.IsolationLevelCharacteristic()}
)
engine_config_types: Mapping[str, Any] = util.immutabledict(
{
"pool_timeout": util.asint,
"echo": util.bool_or_str("debug"),
"echo_pool": util.bool_or_str("debug"),
"pool_recycle": util.asint,
"pool_size": util.asint,
"max_overflow": util.asint,
"future": util.asbool,
}
)
# if the NUMERIC type
# returns decimal.Decimal.
# *not* the FLOAT type however.
supports_native_decimal = False
name = "default"
# length at which to truncate
# any identifier.
max_identifier_length = 9999
_user_defined_max_identifier_length: Optional[int] = None
isolation_level: Optional[str] = None
# sub-categories of max_identifier_length.
# currently these accommodate for MySQL which allows alias names
# of 255 but DDL names only of 64.
max_index_name_length: Optional[int] = None
max_constraint_name_length: Optional[int] = None
supports_sane_rowcount = True
supports_sane_multi_rowcount = True
colspecs: MutableMapping[Type[TypeEngine[Any]], Type[TypeEngine[Any]]] = {}
default_paramstyle = "named"
supports_default_values = False
"""dialect supports INSERT... DEFAULT VALUES syntax"""
supports_default_metavalue = False
"""dialect supports INSERT... VALUES (DEFAULT) syntax"""
default_metavalue_token = "DEFAULT"
"""for INSERT... VALUES (DEFAULT) syntax, the token to put in the
parenthesis."""
# not sure if this is a real thing but the compiler will deliver it
# if this is the only flag enabled.
supports_empty_insert = True
"""dialect supports INSERT () VALUES ()"""
supports_multivalues_insert = False
use_insertmanyvalues: bool = False
use_insertmanyvalues_wo_returning: bool = False
insertmanyvalues_page_size: int = 1000
insertmanyvalues_max_parameters = 32700
supports_is_distinct_from = True
supports_server_side_cursors = False
server_side_cursors = False
# extra record-level locking features (#4860)
supports_for_update_of = False
server_version_info = None
default_schema_name: Optional[str] = None
# indicates symbol names are
# UPPERCASEd if they are case insensitive
# within the database.
# if this is True, the methods normalize_name()
# and denormalize_name() must be provided.
requires_name_normalize = False
is_async = False
has_terminate = False
# TODO: this is not to be part of 2.0. implement rudimentary binary
# literals for SQLite, PostgreSQL, MySQL only within
# _Binary.literal_processor
_legacy_binary_type_literal_encoding = "utf-8"
@util.deprecated_params(
empty_in_strategy=(
"1.4",
"The :paramref:`_sa.create_engine.empty_in_strategy` keyword is "
"deprecated, and no longer has any effect. All IN expressions "
"are now rendered using "
'the "expanding parameter" strategy which renders a set of bound'
'expressions, or an "empty set" SELECT, at statement execution'
"time.",
),
server_side_cursors=(
"1.4",
"The :paramref:`_sa.create_engine.server_side_cursors` parameter "
"is deprecated and will be removed in a future release. Please "
"use the "
":paramref:`_engine.Connection.execution_options.stream_results` "
"parameter.",
),
)
def __init__(
self,
paramstyle: Optional[_ParamStyle] = None,
isolation_level: Optional[IsolationLevel] = None,
dbapi: Optional[ModuleType] = None,
implicit_returning: Literal[True] = True,
supports_native_boolean: Optional[bool] = None,
max_identifier_length: Optional[int] = None,
label_length: Optional[int] = None,
insertmanyvalues_page_size: Union[_NoArg, int] = _NoArg.NO_ARG,
use_insertmanyvalues: Optional[bool] = None,
# util.deprecated_params decorator cannot render the
# Linting.NO_LINTING constant
compiler_linting: Linting = int(compiler.NO_LINTING), # type: ignore
server_side_cursors: bool = False,
**kwargs: Any,
):
if server_side_cursors:
if not self.supports_server_side_cursors:
raise exc.ArgumentError(
"Dialect %s does not support server side cursors" % self
)
else:
self.server_side_cursors = True
if getattr(self, "use_setinputsizes", False):
util.warn_deprecated(
"The dialect-level use_setinputsizes attribute is "
"deprecated. Please use "
"bind_typing = BindTyping.SETINPUTSIZES",
"2.0",
)
self.bind_typing = interfaces.BindTyping.SETINPUTSIZES
self.positional = False
self._ischema = None
self.dbapi = dbapi
if paramstyle is not None:
self.paramstyle = paramstyle
elif self.dbapi is not None:
self.paramstyle = self.dbapi.paramstyle
else:
self.paramstyle = self.default_paramstyle
self.positional = self.paramstyle in (
"qmark",
"format",
"numeric",
"numeric_dollar",
)
self.identifier_preparer = self.preparer(self)
self._on_connect_isolation_level = isolation_level
legacy_tt_callable = getattr(self, "type_compiler", None)
if legacy_tt_callable is not None:
tt_callable = cast(
Type[compiler.GenericTypeCompiler],
self.type_compiler,
)
else:
tt_callable = self.type_compiler_cls
self.type_compiler_instance = self.type_compiler = tt_callable(self)
if supports_native_boolean is not None:
self.supports_native_boolean = supports_native_boolean
self._user_defined_max_identifier_length = max_identifier_length
if self._user_defined_max_identifier_length:
self.max_identifier_length = (
self._user_defined_max_identifier_length
)
self.label_length = label_length
self.compiler_linting = compiler_linting
if use_insertmanyvalues is not None:
self.use_insertmanyvalues = use_insertmanyvalues
if insertmanyvalues_page_size is not _NoArg.NO_ARG:
self.insertmanyvalues_page_size = insertmanyvalues_page_size
@property
@util.deprecated(
"2.0",
"full_returning is deprecated, please use insert_returning, "
"update_returning, delete_returning",
)
def full_returning(self):
return (
self.insert_returning
and self.update_returning
and self.delete_returning
)
@property
def insert_executemany_returning(self):
return (
self.insert_returning
and self.supports_multivalues_insert
and self.use_insertmanyvalues
)
update_executemany_returning = False
delete_executemany_returning = False
@util.memoized_property
def loaded_dbapi(self) -> ModuleType:
if self.dbapi is None:
raise exc.InvalidRequestError(
f"Dialect {self} does not have a Python DBAPI established "
"and cannot be used for actual database interaction"
)
return self.dbapi
@util.memoized_property
def _bind_typing_render_casts(self):
return self.bind_typing is interfaces.BindTyping.RENDER_CASTS
def _ensure_has_table_connection(self, arg):
if not isinstance(arg, Connection):
raise exc.ArgumentError(
"The argument passed to Dialect.has_table() should be a "
"%s, got %s. "
"Additionally, the Dialect.has_table() method is for "
"internal dialect "
"use only; please use "
"``inspect(some_engine).has_table(<tablename>>)`` "
"for public API use." % (Connection, type(arg))
)
@util.memoized_property
def _supports_statement_cache(self):
ssc = self.__class__.__dict__.get("supports_statement_cache", None)
if ssc is None:
util.warn(
"Dialect %s:%s will not make use of SQL compilation caching "
"as it does not set the 'supports_statement_cache' attribute "
"to ``True``. This can have "
"significant performance implications including some "
"performance degradations in comparison to prior SQLAlchemy "
"versions. Dialect maintainers should seek to set this "
"attribute to True after appropriate development and testing "
"for SQLAlchemy 1.4 caching support. Alternatively, this "
"attribute may be set to False which will disable this "
"warning." % (self.name, self.driver),
code="cprf",
)
return bool(ssc)
@util.memoized_property
def _type_memos(self):
return weakref.WeakKeyDictionary()
@property
def dialect_description(self):
return self.name + "+" + self.driver
@property
def supports_sane_rowcount_returning(self):
"""True if this dialect supports sane rowcount even if RETURNING is
in use.
For dialects that don't support RETURNING, this is synonymous with
``supports_sane_rowcount``.
"""
return self.supports_sane_rowcount
@classmethod
def get_pool_class(cls, url: URL) -> Type[Pool]:
return getattr(cls, "poolclass", pool.QueuePool)
def get_dialect_pool_class(self, url: URL) -> Type[Pool]:
return self.get_pool_class(url)
@classmethod
def load_provisioning(cls):
package = ".".join(cls.__module__.split(".")[0:-1])
try:
__import__(package + ".provision")
except ImportError:
pass
def _builtin_onconnect(self) -> Optional[_ListenerFnType]:
if self._on_connect_isolation_level is not None:
def builtin_connect(dbapi_conn, conn_rec):
self._assert_and_set_isolation_level(
dbapi_conn, self._on_connect_isolation_level
)
return builtin_connect
else:
return None
def initialize(self, connection):
try:
self.server_version_info = self._get_server_version_info(
connection
)
except NotImplementedError:
self.server_version_info = None
try:
self.default_schema_name = self._get_default_schema_name(
connection
)
except NotImplementedError:
self.default_schema_name = None
try:
self.default_isolation_level = self.get_default_isolation_level(
connection.connection.dbapi_connection
)
except NotImplementedError:
self.default_isolation_level = None
if not self._user_defined_max_identifier_length:
max_ident_length = self._check_max_identifier_length(connection)
if max_ident_length:
self.max_identifier_length = max_ident_length
if (
self.label_length
and self.label_length > self.max_identifier_length
):
raise exc.ArgumentError(
"Label length of %d is greater than this dialect's"
" maximum identifier length of %d"
% (self.label_length, self.max_identifier_length)
)
def on_connect(self):
# inherits the docstring from interfaces.Dialect.on_connect
return None
def _check_max_identifier_length(self, connection):
"""Perform a connection / server version specific check to determine
the max_identifier_length.
If the dialect's class level max_identifier_length should be used,
can return None.
.. versionadded:: 1.3.9
"""
return None
def get_default_isolation_level(self, dbapi_conn):
"""Given a DBAPI connection, return its isolation level, or
a default isolation level if one cannot be retrieved.
May be overridden by subclasses in order to provide a
"fallback" isolation level for databases that cannot reliably
retrieve the actual isolation level.
By default, calls the :meth:`_engine.Interfaces.get_isolation_level`
method, propagating any exceptions raised.
.. versionadded:: 1.3.22
"""
return self.get_isolation_level(dbapi_conn)
def type_descriptor(self, typeobj):
"""Provide a database-specific :class:`.TypeEngine` object, given
the generic object which comes from the types module.
This method looks for a dictionary called
``colspecs`` as a class or instance-level variable,
and passes on to :func:`_types.adapt_type`.
"""
return type_api.adapt_type(typeobj, self.colspecs)
def has_index(self, connection, table_name, index_name, schema=None, **kw):
if not self.has_table(connection, table_name, schema=schema, **kw):
return False
for idx in self.get_indexes(
connection, table_name, schema=schema, **kw
):
if idx["name"] == index_name:
return True
else:
return False
def has_schema(
self, connection: Connection, schema_name: str, **kw: Any
) -> bool:
return schema_name in self.get_schema_names(connection, **kw)
def validate_identifier(self, ident):
if len(ident) > self.max_identifier_length:
raise exc.IdentifierError(
"Identifier '%s' exceeds maximum length of %d characters"
% (ident, self.max_identifier_length)
)
def connect(self, *cargs, **cparams):
# inherits the docstring from interfaces.Dialect.connect
return self.loaded_dbapi.connect(*cargs, **cparams)
def create_connect_args(self, url):
# inherits the docstring from interfaces.Dialect.create_connect_args
opts = url.translate_connect_args()
opts.update(url.query)
return [[], opts]
def set_engine_execution_options(
self, engine: Engine, opts: Mapping[str, Any]
) -> None:
supported_names = set(self.connection_characteristics).intersection(
opts
)
if supported_names:
characteristics: Mapping[str, Any] = util.immutabledict(
(name, opts[name]) for name in supported_names
)
@event.listens_for(engine, "engine_connect")
def set_connection_characteristics(connection):
self._set_connection_characteristics(
connection, characteristics
)
def set_connection_execution_options(
self, connection: Connection, opts: Mapping[str, Any]
) -> None:
supported_names = set(self.connection_characteristics).intersection(
opts
)
if supported_names:
characteristics: Mapping[str, Any] = util.immutabledict(
(name, opts[name]) for name in supported_names
)
self._set_connection_characteristics(connection, characteristics)
def _set_connection_characteristics(self, connection, characteristics):
characteristic_values = [
(name, self.connection_characteristics[name], value)
for name, value in characteristics.items()
]
if connection.in_transaction():
trans_objs = [
(name, obj)
for name, obj, value in characteristic_values
if obj.transactional
]
if trans_objs:
raise exc.InvalidRequestError(
"This connection has already initialized a SQLAlchemy "
"Transaction() object via begin() or autobegin; "
"%s may not be altered unless rollback() or commit() "
"is called first."
% (", ".join(name for name, obj in trans_objs))
)
dbapi_connection = connection.connection.dbapi_connection
for name, characteristic, value in characteristic_values:
characteristic.set_characteristic(self, dbapi_connection, value)
connection.connection._connection_record.finalize_callback.append(
functools.partial(self._reset_characteristics, characteristics)
)
def _reset_characteristics(self, characteristics, dbapi_connection):
for characteristic_name in characteristics:
characteristic = self.connection_characteristics[
characteristic_name
]
characteristic.reset_characteristic(self, dbapi_connection)
def do_begin(self, dbapi_connection):
pass
def do_rollback(self, dbapi_connection):
dbapi_connection.rollback()
def do_commit(self, dbapi_connection):
dbapi_connection.commit()
def do_terminate(self, dbapi_connection):
self.do_close(dbapi_connection)
def do_close(self, dbapi_connection):
dbapi_connection.close()
@util.memoized_property
def _dialect_specific_select_one(self):
return str(expression.select(1).compile(dialect=self))
def _do_ping_w_event(self, dbapi_connection: DBAPIConnection) -> bool:
try:
return self.do_ping(dbapi_connection)
except self.loaded_dbapi.Error as err:
is_disconnect = self.is_disconnect(err, dbapi_connection, None)
if self._has_events:
try:
Connection._handle_dbapi_exception_noconnection(
err,
self,
is_disconnect=is_disconnect,
invalidate_pool_on_disconnect=False,
is_pre_ping=True,
)
except exc.StatementError as new_err:
is_disconnect = new_err.connection_invalidated
if is_disconnect:
return False
else:
raise
def do_ping(self, dbapi_connection: DBAPIConnection) -> bool:
cursor = None
cursor = dbapi_connection.cursor()
try:
cursor.execute(self._dialect_specific_select_one)
finally:
cursor.close()
return True
def create_xid(self):
"""Create a random two-phase transaction ID.
This id will be passed to do_begin_twophase(), do_rollback_twophase(),
do_commit_twophase(). Its format is unspecified.
"""
return "_sa_%032x" % random.randint(0, 2**128)
def do_savepoint(self, connection, name):
connection.execute(expression.SavepointClause(name))
def do_rollback_to_savepoint(self, connection, name):
connection.execute(expression.RollbackToSavepointClause(name))
def do_release_savepoint(self, connection, name):
connection.execute(expression.ReleaseSavepointClause(name))
def _deliver_insertmanyvalues_batches(
self, cursor, statement, parameters, generic_setinputsizes, context
):
context = cast(DefaultExecutionContext, context)
compiled = cast(SQLCompiler, context.compiled)
is_returning: Final[bool] = bool(compiled.effective_returning)
batch_size = context.execution_options.get(
"insertmanyvalues_page_size", self.insertmanyvalues_page_size
)
if is_returning:
context._insertmanyvalues_rows = result = []
for batch_rec in compiled._deliver_insertmanyvalues_batches(
statement, parameters, generic_setinputsizes, batch_size
):
yield batch_rec
if is_returning:
result.extend(cursor.fetchall())
def do_executemany(self, cursor, statement, parameters, context=None):
cursor.executemany(statement, parameters)
def do_execute(self, cursor, statement, parameters, context=None):
cursor.execute(statement, parameters)
def do_execute_no_params(self, cursor, statement, context=None):
cursor.execute(statement)
def is_disconnect(self, e, connection, cursor):
return False
@util.memoized_instancemethod
def _gen_allowed_isolation_levels(self, dbapi_conn):
try:
raw_levels = list(self.get_isolation_level_values(dbapi_conn))
except NotImplementedError:
return None
else:
normalized_levels = [
level.replace("_", " ").upper() for level in raw_levels
]
if raw_levels != normalized_levels:
raise ValueError(
f"Dialect {self.name!r} get_isolation_level_values() "
f"method should return names as UPPERCASE using spaces, "
f"not underscores; got "
f"{sorted(set(raw_levels).difference(normalized_levels))}"
)
return tuple(normalized_levels)
def _assert_and_set_isolation_level(self, dbapi_conn, level):
level = level.replace("_", " ").upper()
_allowed_isolation_levels = self._gen_allowed_isolation_levels(
dbapi_conn
)
if (
_allowed_isolation_levels
and level not in _allowed_isolation_levels
):
raise exc.ArgumentError(
f"Invalid value {level!r} for isolation_level. "
f"Valid isolation levels for {self.name!r} are "
f"{', '.join(_allowed_isolation_levels)}"
)
self.set_isolation_level(dbapi_conn, level)
def reset_isolation_level(self, dbapi_conn):
# default_isolation_level is read from the first connection
# after the initial set of 'isolation_level', if any, so is
# the configured default of this dialect.
self._assert_and_set_isolation_level(
dbapi_conn, self.default_isolation_level
)
def normalize_name(self, name):
if name is None:
return None
name_lower = name.lower()
name_upper = name.upper()
if name_upper == name_lower:
# name has no upper/lower conversion, e.g. non-european characters.
# return unchanged
return name
elif name_upper == name and not (
self.identifier_preparer._requires_quotes
)(name_lower):
# name is all uppercase and doesn't require quoting; normalize
# to all lower case
return name_lower
elif name_lower == name:
# name is all lower case, which if denormalized means we need to
# force quoting on it
return quoted_name(name, quote=True)
else:
# name is mixed case, means it will be quoted in SQL when used
# later, no normalizes
return name
def denormalize_name(self, name):
if name is None:
return None
name_lower = name.lower()
name_upper = name.upper()
if name_upper == name_lower:
# name has no upper/lower conversion, e.g. non-european characters.
# return unchanged
return name
elif name_lower == name and not (
self.identifier_preparer._requires_quotes
)(name_lower):
name = name_upper
return name
def get_driver_connection(self, connection):
return connection
def _overrides_default(self, method):
return (
getattr(type(self), method).__code__
is not getattr(DefaultDialect, method).__code__
)
def _default_multi_reflect(
self,
single_tbl_method,
connection,
kind,
schema,
filter_names,
scope,
**kw,
):
names_fns = []
temp_names_fns = []
if ObjectKind.TABLE in kind:
names_fns.append(self.get_table_names)
temp_names_fns.append(self.get_temp_table_names)
if ObjectKind.VIEW in kind:
names_fns.append(self.get_view_names)
temp_names_fns.append(self.get_temp_view_names)
if ObjectKind.MATERIALIZED_VIEW in kind:
names_fns.append(self.get_materialized_view_names)
# no temp materialized view at the moment
# temp_names_fns.append(self.get_temp_materialized_view_names)
unreflectable = kw.pop("unreflectable", {})
if (
filter_names
and scope is ObjectScope.ANY
and kind is ObjectKind.ANY
):
# if names are given and no qualification on type of table
# (i.e. the Table(..., autoload) case), take the names as given,
# don't run names queries. If a table does not exit
# NoSuchTableError is raised and it's skipped
# this also suits the case for mssql where we can reflect
# individual temp tables but there's no temp_names_fn
names = filter_names
else:
names = []
name_kw = {"schema": schema, **kw}
fns = []
if ObjectScope.DEFAULT in scope:
fns.extend(names_fns)
if ObjectScope.TEMPORARY in scope:
fns.extend(temp_names_fns)
for fn in fns:
try:
names.extend(fn(connection, **name_kw))
except NotImplementedError:
pass
if filter_names:
filter_names = set(filter_names)
# iterate over all the tables/views and call the single table method
for table in names:
if not filter_names or table in filter_names:
key = (schema, table)
try:
yield (
key,
single_tbl_method(
connection, table, schema=schema, **kw
),
)
except exc.UnreflectableTableError as err:
if key not in unreflectable:
unreflectable[key] = err
except exc.NoSuchTableError:
pass
def get_multi_table_options(self, connection, **kw):
return self._default_multi_reflect(
self.get_table_options, connection, **kw
)
def get_multi_columns(self, connection, **kw):
return self._default_multi_reflect(self.get_columns, connection, **kw)
def get_multi_pk_constraint(self, connection, **kw):
return self._default_multi_reflect(
self.get_pk_constraint, connection, **kw
)
def get_multi_foreign_keys(self, connection, **kw):
return self._default_multi_reflect(
self.get_foreign_keys, connection, **kw
)
def get_multi_indexes(self, connection, **kw):
return self._default_multi_reflect(self.get_indexes, connection, **kw)
def get_multi_unique_constraints(self, connection, **kw):
return self._default_multi_reflect(
self.get_unique_constraints, connection, **kw
)
def get_multi_check_constraints(self, connection, **kw):
return self._default_multi_reflect(
self.get_check_constraints, connection, **kw
)
def get_multi_table_comment(self, connection, **kw):
return self._default_multi_reflect(
self.get_table_comment, connection, **kw
)
class StrCompileDialect(DefaultDialect):
statement_compiler = compiler.StrSQLCompiler
ddl_compiler = compiler.DDLCompiler
type_compiler_cls = compiler.StrSQLTypeCompiler
preparer = compiler.IdentifierPreparer
insert_returning = True
update_returning = True
delete_returning = True
supports_statement_cache = True
supports_identity_columns = True
supports_sequences = True
sequences_optional = True
preexecute_autoincrement_sequences = False
supports_native_boolean = True
supports_multivalues_insert = True
supports_simple_order_by_label = True
class DefaultExecutionContext(ExecutionContext):
isinsert = False
isupdate = False
isdelete = False
is_crud = False
is_text = False
isddl = False
execute_style: ExecuteStyle = ExecuteStyle.EXECUTE
compiled: Optional[Compiled] = None
result_column_struct: Optional[
Tuple[List[ResultColumnsEntry], bool, bool, bool, bool]
] = None
returned_default_rows: Optional[Sequence[Row[Any]]] = None
execution_options: _ExecuteOptions = util.EMPTY_DICT
cursor_fetch_strategy = _cursor._DEFAULT_FETCH
invoked_statement: Optional[Executable] = None
_is_implicit_returning = False
_is_explicit_returning = False
_is_supplemental_returning = False
_is_server_side = False
_soft_closed = False
_has_rowcount = False
# a hook for SQLite's translation of
# result column names
# NOTE: pyhive is using this hook, can't remove it :(
_translate_colname: Optional[Callable[[str], str]] = None
_expanded_parameters: Mapping[str, List[str]] = util.immutabledict()
"""used by set_input_sizes().
This collection comes from ``ExpandedState.parameter_expansion``.
"""
cache_hit = NO_CACHE_KEY
root_connection: Connection
_dbapi_connection: PoolProxiedConnection
dialect: Dialect
unicode_statement: str
cursor: DBAPICursor
compiled_parameters: List[_MutableCoreSingleExecuteParams]
parameters: _DBAPIMultiExecuteParams
extracted_parameters: Optional[Sequence[BindParameter[Any]]]
_empty_dict_params = cast("Mapping[str, Any]", util.EMPTY_DICT)
_insertmanyvalues_rows: Optional[List[Tuple[Any, ...]]] = None
@classmethod
def _init_ddl(
cls,
dialect: Dialect,
connection: Connection,
dbapi_connection: PoolProxiedConnection,
execution_options: _ExecuteOptions,
compiled_ddl: DDLCompiler,
) -> ExecutionContext:
"""Initialize execution context for an ExecutableDDLElement
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 = execution_options
self.unicode_statement = str(compiled)
if compiled.schema_translate_map:
schema_translate_map = self.execution_options.get(
"schema_translate_map", {}
)
rst = compiled.preparer._render_schema_translates
self.unicode_statement = rst(
self.unicode_statement, schema_translate_map
)
self.statement = self.unicode_statement
self.cursor = self.create_cursor()
self.compiled_parameters = []
if dialect.positional:
self.parameters = [dialect.execute_sequence_format()]
else:
self.parameters = [self._empty_dict_params]
return self
@classmethod
def _init_compiled(
cls,
dialect: Dialect,
connection: Connection,
dbapi_connection: PoolProxiedConnection,
execution_options: _ExecuteOptions,
compiled: SQLCompiler,
parameters: _CoreMultiExecuteParams,
invoked_statement: Executable,
extracted_parameters: Optional[Sequence[BindParameter[Any]]],
cache_hit: CacheStats = CacheStats.CACHING_DISABLED,
) -> ExecutionContext:
"""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.extracted_parameters = extracted_parameters
self.invoked_statement = invoked_statement
self.compiled = compiled
self.cache_hit = cache_hit
self.execution_options = execution_options
self.result_column_struct = (
compiled._result_columns,
compiled._ordered_columns,
compiled._textual_ordered_columns,
compiled._ad_hoc_textual,
compiled._loose_column_name_matching,
)
self.isinsert = ii = compiled.isinsert
self.isupdate = iu = compiled.isupdate
self.isdelete = id_ = compiled.isdelete
self.is_text = compiled.isplaintext
if ii or iu or id_:
dml_statement = compiled.compile_state.statement # type: ignore
if TYPE_CHECKING:
assert isinstance(dml_statement, UpdateBase)
self.is_crud = True
self._is_explicit_returning = ier = bool(dml_statement._returning)
self._is_implicit_returning = iir = bool(
compiled.implicit_returning
)
if iir and dml_statement._supplemental_returning:
self._is_supplemental_returning = True
# dont mix implicit and explicit returning
assert not (iir and ier)
if (ier or iir) and compiled.for_executemany:
if ii and not self.dialect.insert_executemany_returning:
raise exc.InvalidRequestError(
f"Dialect {self.dialect.dialect_description} with "
f"current server capabilities does not support "
"INSERT..RETURNING when executemany is used"
)
elif (
ii
and self.dialect.use_insertmanyvalues
and not compiled._insertmanyvalues
):
raise exc.InvalidRequestError(
'Statement does not have "insertmanyvalues" '
"enabled, can't use INSERT..RETURNING with "
"executemany in this case."
)
elif iu and not self.dialect.update_executemany_returning:
raise exc.InvalidRequestError(
f"Dialect {self.dialect.dialect_description} with "
f"current server capabilities does not support "
"UPDATE..RETURNING when executemany is used"
)
elif id_ and not self.dialect.delete_executemany_returning:
raise exc.InvalidRequestError(
f"Dialect {self.dialect.dialect_description} with "
f"current server capabilities does not support "
"DELETE..RETURNING when executemany is used"
)
if not parameters:
self.compiled_parameters = [
compiled.construct_params(
extracted_parameters=extracted_parameters,
escape_names=False,
)
]
else:
self.compiled_parameters = [
compiled.construct_params(
m,
escape_names=False,
_group_number=grp,
extracted_parameters=extracted_parameters,
)
for grp, m in enumerate(parameters)
]
if len(parameters) > 1:
if self.isinsert and compiled._insertmanyvalues:
self.execute_style = ExecuteStyle.INSERTMANYVALUES
else:
self.execute_style = ExecuteStyle.EXECUTEMANY
self.unicode_statement = compiled.string
self.cursor = self.create_cursor()
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
flattened_processors: Mapping[
str, _BindProcessorType[Any]
] = processors # type: ignore[assignment]
if compiled.literal_execute_params or compiled.post_compile_params:
if self.executemany:
raise exc.InvalidRequestError(
"'literal_execute' or 'expanding' parameters can't be "
"used with executemany()"
)
expanded_state = compiled._process_parameters_for_postcompile(
self.compiled_parameters[0]
)
# re-assign self.unicode_statement
self.unicode_statement = expanded_state.statement
self._expanded_parameters = expanded_state.parameter_expansion
flattened_processors = dict(processors) # type: ignore
flattened_processors.update(expanded_state.processors)
positiontup = expanded_state.positiontup
elif compiled.positional:
positiontup = self.compiled.positiontup
else:
positiontup = None
if compiled.schema_translate_map:
schema_translate_map = self.execution_options.get(
"schema_translate_map", {}
)
rst = compiled.preparer._render_schema_translates
self.unicode_statement = rst(
self.unicode_statement, schema_translate_map
)
# final self.unicode_statement is now assigned, encode if needed
# by dialect
self.statement = self.unicode_statement
# Convert the dictionary of bind parameter values
# into a dict or list to be sent to the DBAPI's
# execute() or executemany() method.
if compiled.positional:
core_positional_parameters: MutableSequence[Sequence[Any]] = []
assert positiontup is not None
for compiled_params in self.compiled_parameters:
l_param: List[Any] = [
flattened_processors[key](compiled_params[key])
if key in flattened_processors
else compiled_params[key]
for key in positiontup
]
core_positional_parameters.append(
dialect.execute_sequence_format(l_param)
)
self.parameters = core_positional_parameters
else:
core_dict_parameters: MutableSequence[Dict[str, Any]] = []
escaped_names = compiled.escaped_bind_names
# note that currently, "expanded" parameters will be present
# in self.compiled_parameters in their quoted form. This is
# slightly inconsistent with the approach taken as of
# #8056 where self.compiled_parameters is meant to contain unquoted
# param names.
d_param: Dict[str, Any]
for compiled_params in self.compiled_parameters:
if escaped_names:
d_param = {
escaped_names.get(key, key): flattened_processors[key](
compiled_params[key]
)
if key in flattened_processors
else compiled_params[key]
for key in compiled_params
}
else:
d_param = {
key: flattened_processors[key](compiled_params[key])
if key in flattened_processors
else compiled_params[key]
for key in compiled_params
}
core_dict_parameters.append(d_param)
self.parameters = core_dict_parameters
return self
@classmethod
def _init_statement(
cls,
dialect: Dialect,
connection: Connection,
dbapi_connection: PoolProxiedConnection,
execution_options: _ExecuteOptions,
statement: str,
parameters: _DBAPIMultiExecuteParams,
) -> ExecutionContext:
"""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
self.execution_options = execution_options
if not parameters:
if self.dialect.positional:
self.parameters = [dialect.execute_sequence_format()]
else:
self.parameters = [self._empty_dict_params]
elif isinstance(parameters[0], dialect.execute_sequence_format):
self.parameters = parameters
elif isinstance(parameters[0], dict):
self.parameters = parameters
else:
self.parameters = [
dialect.execute_sequence_format(p) for p in parameters
]
if len(parameters) > 1:
self.execute_style = ExecuteStyle.EXECUTEMANY
self.statement = self.unicode_statement = statement
self.cursor = self.create_cursor()
return self
@classmethod
def _init_default(
cls,
dialect: Dialect,
connection: Connection,
dbapi_connection: PoolProxiedConnection,
execution_options: _ExecuteOptions,
) -> ExecutionContext:
"""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 = execution_options
self.cursor = self.create_cursor()
return self
def _get_cache_stats(self) -> str:
if self.compiled is None:
return "raw sql"
now = perf_counter()
ch = self.cache_hit
gen_time = self.compiled._gen_time
assert gen_time is not None
if ch is NO_CACHE_KEY:
return "no key %.5fs" % (now - gen_time,)
elif ch is CACHE_HIT:
return "cached since %.4gs ago" % (now - gen_time,)
elif ch is CACHE_MISS:
return "generated in %.5fs" % (now - gen_time,)
elif ch is CACHING_DISABLED:
return "caching disabled %.5fs" % (now - gen_time,)
elif ch is NO_DIALECT_SUPPORT:
return "dialect %s+%s does not support caching %.5fs" % (
self.dialect.name,
self.dialect.driver,
now - gen_time,
)
else:
return "unknown"
@property
def executemany(self):
return self.execute_style in (
ExecuteStyle.EXECUTEMANY,
ExecuteStyle.INSERTMANYVALUES,
)
@util.memoized_property
def identifier_preparer(self):
if self.compiled:
return self.compiled.preparer
elif "schema_translate_map" in self.execution_options:
return self.dialect.identifier_preparer._with_schema_translate(
self.execution_options["schema_translate_map"]
)
else:
return self.dialect.identifier_preparer
@util.memoized_property
def engine(self):
return self.root_connection.engine
@util.memoized_property
def postfetch_cols(self) -> Optional[Sequence[Column[Any]]]:
if TYPE_CHECKING:
assert isinstance(self.compiled, SQLCompiler)
return self.compiled.postfetch
@util.memoized_property
def prefetch_cols(self) -> Optional[Sequence[Column[Any]]]:
if TYPE_CHECKING:
assert isinstance(self.compiled, SQLCompiler)
if self.isinsert:
return self.compiled.insert_prefetch
elif self.isupdate:
return self.compiled.update_prefetch
else:
return ()
@util.memoized_property
def no_parameters(self):
return self.execution_options.get("no_parameters", False)
def _execute_scalar(self, stmt, type_, parameters=None):
"""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 "schema_translate_map" in self.execution_options:
schema_translate_map = self.execution_options.get(
"schema_translate_map", {}
)
rst = self.identifier_preparer._render_schema_translates
stmt = rst(stmt, schema_translate_map)
if not parameters:
if self.dialect.positional:
parameters = self.dialect.execute_sequence_format()
else:
parameters = {}
conn._cursor_execute(self.cursor, stmt, parameters, context=self)
row = self.cursor.fetchone()
if row is not None:
r = row[0]
else:
r = None
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
@util.memoized_property
def connection(self):
return self.root_connection
def _use_server_side_cursor(self):
if not self.dialect.supports_server_side_cursors:
return False
if self.dialect.server_side_cursors:
# this is deprecated
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.unicode_statement
and SERVER_SIDE_CURSOR_RE.match(self.unicode_statement)
)
)
else:
use_server_side = self.execution_options.get(
"stream_results", False
)
return use_server_side
def create_cursor(self):
if (
# inlining initial preference checks for SS cursors
self.dialect.supports_server_side_cursors
and (
self.execution_options.get("stream_results", False)
or (
self.dialect.server_side_cursors
and self._use_server_side_cursor()
)
)
):
self._is_server_side = True
return self.create_server_side_cursor()
else:
self._is_server_side = False
return self.create_default_cursor()
def create_default_cursor(self):
return self._dbapi_connection.cursor()
def create_server_side_cursor(self):
raise NotImplementedError()
def pre_exec(self):
pass
def get_out_parameter_values(self, names):
raise NotImplementedError(
"This dialect does not support OUT parameters"
)
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 for an INSERT statement that would need to
return the last inserted primary key for those dialects that make use
of the lastrowid concept. In these cases, it is called directly after
:meth:`.ExecutionContext.post_exec`.
"""
return self.cursor.lastrowid
def handle_dbapi_exception(self, e):
pass
@util.non_memoized_property
def rowcount(self) -> int:
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_result_proxy(self):
exec_opt = self.execution_options
if self.is_crud or self.is_text:
result = self._setup_dml_or_text_result()
yp = sr = False
else:
yp = exec_opt.get("yield_per", None)
sr = self._is_server_side or exec_opt.get("stream_results", False)
strategy = self.cursor_fetch_strategy
if sr and strategy is _cursor._DEFAULT_FETCH:
strategy = _cursor.BufferedRowCursorFetchStrategy(
self.cursor, self.execution_options
)
cursor_description: _DBAPICursorDescription = (
strategy.alternate_cursor_description
or self.cursor.description
)
if cursor_description is None:
strategy = _cursor._NO_CURSOR_DQL
result = _cursor.CursorResult(self, strategy, cursor_description)
compiled = self.compiled
if (
compiled
and not self.isddl
and cast(SQLCompiler, compiled).has_out_parameters
):
self._setup_out_parameters(result)
self._soft_closed = result._soft_closed
if yp:
result = result.yield_per(yp)
return result
def _setup_out_parameters(self, result):
compiled = cast(SQLCompiler, self.compiled)
out_bindparams = [
(param, name)
for param, name in compiled.bind_names.items()
if param.isoutparam
]
out_parameters = {}
for bindparam, raw_value in zip(
[param for param, name in out_bindparams],
self.get_out_parameter_values(
[name for param, name in out_bindparams]
),
):
type_ = bindparam.type
impl_type = type_.dialect_impl(self.dialect)
dbapi_type = impl_type.get_dbapi_type(self.dialect.loaded_dbapi)
result_processor = impl_type.result_processor(
self.dialect, dbapi_type
)
if result_processor is not None:
raw_value = result_processor(raw_value)
out_parameters[bindparam.key] = raw_value
result.out_parameters = out_parameters
def _setup_dml_or_text_result(self):
compiled = cast(SQLCompiler, self.compiled)
strategy = self.cursor_fetch_strategy
if self.isinsert:
if (
self.execute_style is ExecuteStyle.INSERTMANYVALUES
and compiled.effective_returning
):
strategy = _cursor.FullyBufferedCursorFetchStrategy(
self.cursor,
initial_buffer=self._insertmanyvalues_rows,
# maintain alt cursor description if set by the
# dialect, e.g. mssql preserves it
alternate_description=(
strategy.alternate_cursor_description
),
)
if compiled.postfetch_lastrowid:
self.inserted_primary_key_rows = (
self._setup_ins_pk_from_lastrowid()
)
# else if not self._is_implicit_returning,
# the default inserted_primary_key_rows accessor will
# return an "empty" primary key collection when accessed.
if self._is_server_side and strategy is _cursor._DEFAULT_FETCH:
strategy = _cursor.BufferedRowCursorFetchStrategy(
self.cursor, self.execution_options
)
cursor_description = (
strategy.alternate_cursor_description or self.cursor.description
)
if cursor_description is None:
strategy = _cursor._NO_CURSOR_DML
result: _cursor.CursorResult[Any] = _cursor.CursorResult(
self, strategy, cursor_description
)
if self.isinsert:
if self._is_implicit_returning:
rows = result.all()
self.returned_default_rows = rows
self.inserted_primary_key_rows = (
self._setup_ins_pk_from_implicit_returning(result, rows)
)
# test that it has a cursor metadata that is accurate. the
# first row will have been fetched and current assumptions
# are that the result has only one row, until executemany()
# support is added here.
assert result._metadata.returns_rows
# Insert statement has both return_defaults() and
# returning(). rewind the result on the list of rows
# we just used.
if self._is_supplemental_returning:
result._rewind(rows)
else:
result._soft_close()
elif not self._is_explicit_returning:
result._soft_close()
# we assume here the result does not return any rows.
# *usually*, this will be true. However, some dialects
# such as that of MSSQL/pyodbc need to SELECT a post fetch
# function so this is not necessarily true.
# assert not result.returns_rows
elif self._is_implicit_returning:
rows = result.all()
if rows:
self.returned_default_rows = rows
result.rowcount = len(rows)
self._has_rowcount = True
if self._is_supplemental_returning:
result._rewind(rows)
else:
result._soft_close()
# test that it has a cursor metadata that is accurate.
# the rows have all been fetched however.
assert result._metadata.returns_rows
elif not result._metadata.returns_rows:
# no results, get rowcount
# (which requires open cursor on some drivers)
result.rowcount
self._has_rowcount = True
result._soft_close()
elif self.isupdate or self.isdelete:
result.rowcount
self._has_rowcount = True
return result
@util.memoized_property
def inserted_primary_key_rows(self):
# if no specific "get primary key" strategy was set up
# during execution, return a "default" primary key based
# on what's in the compiled_parameters and nothing else.
return self._setup_ins_pk_from_empty()
def _setup_ins_pk_from_lastrowid(self):
getter = cast(
SQLCompiler, self.compiled
)._inserted_primary_key_from_lastrowid_getter
lastrowid = self.get_lastrowid()
return [getter(lastrowid, self.compiled_parameters[0])]
def _setup_ins_pk_from_empty(self):
getter = cast(
SQLCompiler, self.compiled
)._inserted_primary_key_from_lastrowid_getter
return [getter(None, param) for param in self.compiled_parameters]
def _setup_ins_pk_from_implicit_returning(self, result, rows):
if not rows:
return []
getter = cast(
SQLCompiler, self.compiled
)._inserted_primary_key_from_returning_getter
compiled_params = self.compiled_parameters
return [
getter(row, param) for row, param in zip(rows, compiled_params)
]
def lastrow_has_defaults(self):
return (self.isinsert or self.isupdate) and bool(
cast(SQLCompiler, self.compiled).postfetch
)
def _prepare_set_input_sizes(
self,
) -> Optional[List[Tuple[str, Any, TypeEngine[Any]]]]:
"""Given a cursor and ClauseParameters, prepare arguments
in order to 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 set
the :attr:`.Dialect.bind_typing` attribute to
:attr:`.BindTyping.SETINPUTSIZES`. cx_Oracle is the only DBAPI
that requires setinputsizes(), pyodbc offers it as an option.
Prior to SQLAlchemy 2.0, the setinputsizes() approach was also used
for pg8000 and asyncpg, which has been changed to inline rendering
of casts.
"""
if self.isddl or self.is_text:
return None
compiled = cast(SQLCompiler, self.compiled)
inputsizes = compiled._get_set_input_sizes_lookup()
if inputsizes is None:
return None
dialect = self.dialect
# all of the rest of this... cython?
if dialect._has_events:
inputsizes = dict(inputsizes)
dialect.dispatch.do_setinputsizes(
inputsizes, self.cursor, self.statement, self.parameters, self
)
if compiled.escaped_bind_names:
escaped_bind_names = compiled.escaped_bind_names
else:
escaped_bind_names = None
if dialect.positional:
items = [
(key, compiled.binds[key])
for key in compiled.positiontup or ()
]
else:
items = [
(key, bindparam)
for bindparam, key in compiled.bind_names.items()
]
generic_inputsizes: List[Tuple[str, Any, TypeEngine[Any]]] = []
for key, bindparam in items:
if bindparam in compiled.literal_execute_params:
continue
if key in self._expanded_parameters:
if is_tuple_type(bindparam.type):
num = len(bindparam.type.types)
dbtypes = inputsizes[bindparam]
generic_inputsizes.extend(
(
(
escaped_bind_names.get(paramname, paramname)
if escaped_bind_names is not None
else paramname
),
dbtypes[idx % num],
bindparam.type.types[idx % num],
)
for idx, paramname in enumerate(
self._expanded_parameters[key]
)
)
else:
dbtype = inputsizes.get(bindparam, None)
generic_inputsizes.extend(
(
(
escaped_bind_names.get(paramname, paramname)
if escaped_bind_names is not None
else paramname
),
dbtype,
bindparam.type,
)
for paramname in self._expanded_parameters[key]
)
else:
dbtype = inputsizes.get(bindparam, None)
escaped_name = (
escaped_bind_names.get(key, key)
if escaped_bind_names is not None
else key
)
generic_inputsizes.append(
(escaped_name, dbtype, bindparam.type)
)
return generic_inputsizes
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:
return self._exec_default_clause_element(column, default, type_)
else:
return default.arg
def _exec_default_clause_element(self, column, default, type_):
# execute a default that's a complete clause element. Here, we have
# to re-implement a miniature version of the compile->parameters->
# cursor.execute() sequence, since we don't want to modify the state
# of the connection / result in progress or create new connection/
# result objects etc.
# .. versionchanged:: 1.4
if not default._arg_is_typed:
default_arg = expression.type_coerce(default.arg, type_)
else:
default_arg = default.arg
compiled = expression.select(default_arg).compile(dialect=self.dialect)
compiled_params = compiled.construct_params()
processors = compiled._bind_processors
if compiled.positional:
parameters = self.dialect.execute_sequence_format(
[
processors[key](compiled_params[key]) # type: ignore
if key in processors
else compiled_params[key]
for key in compiled.positiontup or ()
]
)
else:
parameters = {
key: processors[key](compiled_params[key]) # type: ignore
if key in processors
else compiled_params[key]
for key in compiled_params
}
return self._execute_scalar(
str(compiled), type_, parameters=parameters
)
current_parameters: Optional[_CoreSingleExecuteParams] = 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:`_schema.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:`_expression.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:`_schema.Column`,
which is usually synonymous
with the name.
:param isolate_multiinsert_groups=True: indicates that multi-valued
INSERT constructs created using :meth:`_expression.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"
)
else:
assert column is not None
assert parameters is not None
compile_state = cast(
"DMLState", cast(SQLCompiler, self.compiled).compile_state
)
assert compile_state is not None
if (
isolate_multiinsert_groups
and dml.isinsert(compile_state)
and compile_state._has_multi_parameters
):
if column._is_multiparam_column:
index = column.index + 1 # type: ignore
d = {column.original.key: parameters[column.key]}
else:
d = {column.key: parameters[column.key]}
index = 0
assert compile_state._dict_parameters is not None
keys = compile_state._dict_parameters.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):
compiled = cast(SQLCompiler, self.compiled)
key_getter = compiled._within_exec_param_key_getter
scalar_defaults: Dict[Column[Any], Any] = {}
insert_prefetch = compiled.insert_prefetch
update_prefetch = 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 default_is_scalar(c.default):
scalar_defaults[c] = c.default.arg
for c in update_prefetch:
if c.onupdate and default_is_scalar(c.onupdate):
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):
compiled = cast(SQLCompiler, self.compiled)
key_getter = compiled._within_exec_param_key_getter
self.current_parameters = (
compiled_parameters
) = self.compiled_parameters[0]
for c in compiled.insert_prefetch:
if c.default and default_is_scalar(c.default):
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 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