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699272e Jan 12, 2018
@zzzeek @jek @dianaclarke @vrajmohan @ndparker @celttechie
481 lines (330 sloc) 14.1 KB
# sqlalchemy/
# Copyright (C) 2005-2018 the SQLAlchemy authors and contributors
# <see AUTHORS file>
# This module is part of SQLAlchemy and is released under
# the MIT License:
"""Exceptions used with SQLAlchemy.
The base exception class is :exc:`.SQLAlchemyError`. Exceptions which are
raised as a result of DBAPI exceptions are all subclasses of
from .util import compat
class SQLAlchemyError(Exception):
"""Generic error class."""
code = None
def __init__(self, *arg, **kw):
code = kw.pop('code', None)
if code is not None:
self.code = code
super(SQLAlchemyError, self).__init__(*arg, **kw)
def _code_str(self):
if not self.code:
return ""
return (
"(Background on this error at: "
"" % (self.code, )
def _message(self):
# get string representation just like Exception.__str__(self),
# but also support if the string has non-ascii chars
if len(self.args) == 1:
return compat.text_type(self.args[0])
return compat.text_type(self.args)
def __str__(self):
message = self._message()
if self.code:
message = (
"%s %s" % (message, self._code_str())
return message
def __unicode__(self):
return self.__str__()
class ArgumentError(SQLAlchemyError):
"""Raised when an invalid or conflicting function argument is supplied.
This error generally corresponds to construction time state errors.
class ObjectNotExecutableError(ArgumentError):
"""Raised when an object is passed to .execute() that can't be
executed as SQL.
.. versionadded:: 1.1
def __init__(self, target):
super(ObjectNotExecutableError, self).__init__(
"Not an executable object: %r" % target
class NoSuchModuleError(ArgumentError):
"""Raised when a dynamically-loaded module (usually a database dialect)
of a particular name cannot be located."""
class NoForeignKeysError(ArgumentError):
"""Raised when no foreign keys can be located between two selectables
during a join."""
class AmbiguousForeignKeysError(ArgumentError):
"""Raised when more than one foreign key matching can be located
between two selectables during a join."""
class CircularDependencyError(SQLAlchemyError):
"""Raised by topological sorts when a circular dependency is detected.
There are two scenarios where this error occurs:
* In a Session flush operation, if two objects are mutually dependent
on each other, they can not be inserted or deleted via INSERT or
DELETE statements alone; an UPDATE will be needed to post-associate
or pre-deassociate one of the foreign key constrained values.
The ``post_update`` flag described at :ref:`post_update` can resolve
this cycle.
* In a :attr:`.MetaData.sorted_tables` operation, two :class:`.ForeignKey`
or :class:`.ForeignKeyConstraint` objects mutually refer to each
other. Apply the ``use_alter=True`` flag to one or both,
see :ref:`use_alter`.
def __init__(self, message, cycles, edges, msg=None, code=None):
if msg is None:
message += " (%s)" % ", ".join(repr(s) for s in cycles)
message = msg
SQLAlchemyError.__init__(self, message, code=code)
self.cycles = cycles
self.edges = edges
def __reduce__(self):
return self.__class__, (None, self.cycles,
self.edges, self.args[0])
class CompileError(SQLAlchemyError):
"""Raised when an error occurs during SQL compilation"""
class UnsupportedCompilationError(CompileError):
"""Raised when an operation is not supported by the given compiler.
.. versionadded:: 0.8.3
def __init__(self, compiler, element_type):
super(UnsupportedCompilationError, self).__init__(
"Compiler %r can't render element of type %s" %
(compiler, element_type))
class IdentifierError(SQLAlchemyError):
"""Raised when a schema name is beyond the max character limit"""
class DisconnectionError(SQLAlchemyError):
"""A disconnect is detected on a raw DB-API connection.
This error is raised and consumed internally by a connection pool. It can
be raised by the :meth:`.PoolEvents.checkout` event so that the host pool
forces a retry; the exception will be caught three times in a row before
the pool gives up and raises :class:`~sqlalchemy.exc.InvalidRequestError`
regarding the connection attempt.
invalidate_pool = False
class InvalidatePoolError(DisconnectionError):
"""Raised when the connection pool should invalidate all stale connections.
A subclass of :class:`.DisconnectionError` that indicates that the
disconnect situation encountered on the connection probably means the
entire pool should be invalidated, as the database has been restarted.
This exception will be handled otherwise the same way as
:class:`.DisconnectionError`, allowing three attempts to reconnect
before giving up.
.. versionadded:: 1.2
invalidate_pool = True
class TimeoutError(SQLAlchemyError):
"""Raised when a connection pool times out on getting a connection."""
class InvalidRequestError(SQLAlchemyError):
"""SQLAlchemy was asked to do something it can't do.
This error generally corresponds to runtime state errors.
class NoInspectionAvailable(InvalidRequestError):
"""A subject passed to :func:`sqlalchemy.inspection.inspect` produced
no context for inspection."""
class ResourceClosedError(InvalidRequestError):
"""An operation was requested from a connection, cursor, or other
object that's in a closed state."""
class NoSuchColumnError(KeyError, InvalidRequestError):
"""A nonexistent column is requested from a ``RowProxy``."""
class NoReferenceError(InvalidRequestError):
"""Raised by ``ForeignKey`` to indicate a reference cannot be resolved."""
class NoReferencedTableError(NoReferenceError):
"""Raised by ``ForeignKey`` when the referred ``Table`` cannot be
def __init__(self, message, tname):
NoReferenceError.__init__(self, message)
self.table_name = tname
def __reduce__(self):
return self.__class__, (self.args[0], self.table_name)
class NoReferencedColumnError(NoReferenceError):
"""Raised by ``ForeignKey`` when the referred ``Column`` cannot be
def __init__(self, message, tname, cname):
NoReferenceError.__init__(self, message)
self.table_name = tname
self.column_name = cname
def __reduce__(self):
return self.__class__, (self.args[0], self.table_name,
class NoSuchTableError(InvalidRequestError):
"""Table does not exist or is not visible to a connection."""
class UnreflectableTableError(InvalidRequestError):
"""Table exists but can't be reflectted for some reason.
.. versionadded:: 1.2
class UnboundExecutionError(InvalidRequestError):
"""SQL was attempted without a database connection to execute it on."""
class DontWrapMixin(object):
"""A mixin class which, when applied to a user-defined Exception class,
will not be wrapped inside of :exc:`.StatementError` if the error is
emitted within the process of executing a statement.
from sqlalchemy.exc import DontWrapMixin
class MyCustomException(Exception, DontWrapMixin):
class MySpecialType(TypeDecorator):
impl = String
def process_bind_param(self, value, dialect):
if value == 'invalid':
raise MyCustomException("invalid!")
# Moved to orm.exc; compatibility definition installed by orm import until 0.6
UnmappedColumnError = None
class StatementError(SQLAlchemyError):
"""An error occurred during execution of a SQL statement.
:class:`StatementError` wraps the exception raised
during execution, and features :attr:`.statement`
and :attr:`.params` attributes which supply context regarding
the specifics of the statement which had an issue.
The wrapped exception object is available in
the :attr:`.orig` attribute.
statement = None
"""The string SQL statement being invoked when this exception occurred."""
params = None
"""The parameter list being used when this exception occurred."""
orig = None
"""The DBAPI exception object."""
def __init__(self, message, statement, params, orig, code=None):
SQLAlchemyError.__init__(self, message, code=code)
self.statement = statement
self.params = params
self.orig = orig
self.detail = []
def add_detail(self, msg):
def __reduce__(self):
return self.__class__, (self.args[0], self.statement,
self.params, self.orig)
def __str__(self):
from sqlalchemy.sql import util
details = [self._message()]
if self.statement:
details.append("[SQL: %r]" % self.statement)
if self.params:
params_repr = util._repr_params(self.params, 10)
details.append("[parameters: %r]" % params_repr)
code_str = self._code_str()
if code_str:
return ' '.join([
"(%s)" % det for det in self.detail
] + details)
class DBAPIError(StatementError):
"""Raised when the execution of a database operation fails.
Wraps exceptions raised by the DB-API underlying the
database operation. Driver-specific implementations of the standard
DB-API exception types are wrapped by matching sub-types of SQLAlchemy's
:class:`DBAPIError` when possible. DB-API's ``Error`` type maps to
:class:`DBAPIError` in SQLAlchemy, otherwise the names are identical. Note
that there is no guarantee that different DB-API implementations will
raise the same exception type for any given error condition.
:class:`DBAPIError` features :attr:`~.StatementError.statement`
and :attr:`~.StatementError.params` attributes which supply context
regarding the specifics of the statement which had an issue, for the
typical case when the error was raised within the context of
emitting a SQL statement.
The wrapped exception object is available in the
:attr:`~.StatementError.orig` attribute. Its type and properties are
DB-API implementation specific.
code = 'dbapi'
def instance(cls, statement, params,
orig, dbapi_base_err,
# Don't ever wrap these, just return them directly as if
# DBAPIError didn't exist.
if (isinstance(orig, BaseException) and
not isinstance(orig, Exception)) or \
isinstance(orig, DontWrapMixin):
return orig
if orig is not None:
# not a DBAPI error, statement is present.
# raise a StatementError
if isinstance(orig, SQLAlchemyError) and statement:
return StatementError(
"(%s.%s) %s" %
(orig.__class__.__module__, orig.__class__.__name__,
statement, params, orig, code=orig.code
elif not isinstance(orig, dbapi_base_err) and statement:
return StatementError(
"(%s.%s) %s" %
(orig.__class__.__module__, orig.__class__.__name__,
statement, params, orig
glob = globals()
for super_ in orig.__class__.__mro__:
name = super_.__name__
if dialect:
name = dialect.dbapi_exception_translation_map.get(
name, name)
if name in glob and issubclass(glob[name], DBAPIError):
cls = glob[name]
return cls(statement, params, orig, connection_invalidated,
def __reduce__(self):
return self.__class__, (self.statement, self.params,
self.orig, self.connection_invalidated)
def __init__(self, statement, params, orig, connection_invalidated=False,
text = str(orig)
except Exception as e:
text = 'Error in str() of DB-API-generated exception: ' + str(e)
'(%s.%s) %s' % (
orig.__class__.__module__, orig.__class__.__name__, text, ),
orig, code=code
self.connection_invalidated = connection_invalidated
class InterfaceError(DBAPIError):
"""Wraps a DB-API InterfaceError."""
code = "rvf5"
class DatabaseError(DBAPIError):
"""Wraps a DB-API DatabaseError."""
code = "4xp6"
class DataError(DatabaseError):
"""Wraps a DB-API DataError."""
code = "9h9h"
class OperationalError(DatabaseError):
"""Wraps a DB-API OperationalError."""
code = "e3q8"
class IntegrityError(DatabaseError):
"""Wraps a DB-API IntegrityError."""
code = "gkpj"
class InternalError(DatabaseError):
"""Wraps a DB-API InternalError."""
code = "2j85"
class ProgrammingError(DatabaseError):
"""Wraps a DB-API ProgrammingError."""
code = "f405"
class NotSupportedError(DatabaseError):
"""Wraps a DB-API NotSupportedError."""
code = "tw8g"
# Warnings
class SADeprecationWarning(DeprecationWarning):
"""Issued once per usage of a deprecated API."""
class SAPendingDeprecationWarning(PendingDeprecationWarning):
"""Issued once per usage of a deprecated API."""
class SAWarning(RuntimeWarning):
"""Issued at runtime."""