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# sqlalchemy/exc.py
# Copyright (C) 2005-2016 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""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
:exc:`.DBAPIError`.
"""
class SQLAlchemyError(Exception):
"""Generic error class."""
class ArgumentError(SQLAlchemyError):
"""Raised when an invalid or conflicting function argument is supplied.
This error generally corresponds to construction time state errors.
"""
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):
if msg is None:
message += " (%s)" % ", ".join(repr(s) for s in cycles)
else:
message = msg
SQLAlchemyError.__init__(self, message)
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.
"""
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
located.
"""
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
located.
"""
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,
self.column_name)
class NoSuchTableError(InvalidRequestError):
"""Table does not exist or is not visible to a connection."""
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.
E.g.::
from sqlalchemy.exc import DontWrapMixin
class MyCustomException(Exception, DontWrapMixin):
pass
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):
SQLAlchemyError.__init__(self, message)
self.statement = statement
self.params = params
self.orig = orig
self.detail = []
def add_detail(self, msg):
self.detail.append(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 = [SQLAlchemyError.__str__(self)]
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)
return ' '.join([
"(%s)" % det for det in self.detail
] + details)
def __unicode__(self):
return self.__str__()
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.
"""
@classmethod
def instance(cls, statement, params,
orig, dbapi_base_err,
connection_invalidated=False,
dialect=None):
# 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 not isinstance(orig, dbapi_base_err) and statement:
return StatementError(
"(%s.%s) %s" %
(orig.__class__.__module__, orig.__class__.__name__,
orig),
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]
break
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):
try:
text = str(orig)
except Exception as e:
text = 'Error in str() of DB-API-generated exception: ' + str(e)
StatementError.__init__(
self,
'(%s.%s) %s' % (
orig.__class__.__module__, orig.__class__.__name__, text, ),
statement,
params,
orig
)
self.connection_invalidated = connection_invalidated
class InterfaceError(DBAPIError):
"""Wraps a DB-API InterfaceError."""
class DatabaseError(DBAPIError):
"""Wraps a DB-API DatabaseError."""
class DataError(DatabaseError):
"""Wraps a DB-API DataError."""
class OperationalError(DatabaseError):
"""Wraps a DB-API OperationalError."""
class IntegrityError(DatabaseError):
"""Wraps a DB-API IntegrityError."""
class InternalError(DatabaseError):
"""Wraps a DB-API InternalError."""
class ProgrammingError(DatabaseError):
"""Wraps a DB-API ProgrammingError."""
class NotSupportedError(DatabaseError):
"""Wraps a DB-API NotSupportedError."""
# 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."""
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