Exceptions used with SQLAlchemy.
The base exception class is SQLAlchemyError
. Exceptions which are
raised as a result of DBAPI exceptions are all subclasses of
DBAPIError
.
sqlalchemy.exc.
AmbiguousForeignKeysError
(*arg, **kw)¶Raised when more than one foreign key matching can be located between two selectables during a join.
sqlalchemy.exc.
ArgumentError
(*arg, **kw)¶Raised when an invalid or conflicting function argument is supplied.
This error generally corresponds to construction time state errors.
sqlalchemy.exc.
AwaitRequired
(*arg, **kw)¶Error raised by the async greenlet spawn if no async operation was awaited when it required one.
sqlalchemy.exc.
CircularDependencyError
(message, cycles, edges, msg=None, code=None)¶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 Rows that point to themselves / Mutually Dependent Rows can resolve
this cycle.
In a MetaData.sorted_tables
operation, two
ForeignKey
or ForeignKeyConstraint
objects mutually refer to each
other. Apply the use_alter=True
flag to one or both,
see Creating/Dropping Foreign Key Constraints via ALTER.
sqlalchemy.exc.
CompileError
(*arg, **kw)¶Raised when an error occurs during SQL compilation
sqlalchemy.exc.
DBAPIError
(statement, params, orig, hide_parameters=False, connection_invalidated=False, code=None, ismulti=None)¶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
DBAPIError
when possible. DB-API’s Error
type maps to
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.
DBAPIError
features StatementError.statement
and 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
StatementError.orig
attribute. Its type and properties are
DB-API implementation specific.
sqlalchemy.exc.
DataError
(statement, params, orig, hide_parameters=False, connection_invalidated=False, code=None, ismulti=None)¶Wraps a DB-API DataError.
sqlalchemy.exc.
DatabaseError
(statement, params, orig, hide_parameters=False, connection_invalidated=False, code=None, ismulti=None)¶Wraps a DB-API DatabaseError.
sqlalchemy.exc.
DisconnectionError
(*arg, **kw)¶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 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 InvalidRequestError
regarding the connection attempt.
Object Name | Description |
---|---|
A mixin class which, when applied to a user-defined Exception class,
will not be wrapped inside of |
|
helper which adds ‘code’ as an attribute and ‘_code_str’ as a method |
sqlalchemy.exc.
DontWrapMixin
¶A mixin class which, when applied to a user-defined Exception class,
will not be wrapped inside of 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!")
sqlalchemy.exc.
HasDescriptionCode
(*arg, **kw)¶helper which adds ‘code’ as an attribute and ‘_code_str’ as a method
sqlalchemy.exc.
IdentifierError
(*arg, **kw)¶Raised when a schema name is beyond the max character limit
sqlalchemy.exc.
IntegrityError
(statement, params, orig, hide_parameters=False, connection_invalidated=False, code=None, ismulti=None)¶Wraps a DB-API IntegrityError.
sqlalchemy.exc.
InterfaceError
(statement, params, orig, hide_parameters=False, connection_invalidated=False, code=None, ismulti=None)¶Wraps a DB-API InterfaceError.
sqlalchemy.exc.
InternalError
(statement, params, orig, hide_parameters=False, connection_invalidated=False, code=None, ismulti=None)¶Wraps a DB-API InternalError.
sqlalchemy.exc.
InvalidRequestError
(*arg, **kw)¶SQLAlchemy was asked to do something it can’t do.
This error generally corresponds to runtime state errors.
sqlalchemy.exc.
InvalidatePoolError
(*arg, **kw)¶Raised when the connection pool should invalidate all stale connections.
A subclass of 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
DisconnectionError
, allowing three attempts to reconnect
before giving up.
New in version 1.2.
sqlalchemy.exc.
MissingGreenlet
(*arg, **kw)¶Error raised by the async greenlet await_ if called while not inside the greenlet spawn context.
sqlalchemy.exc.
MovedIn20Warning
(*arg, **kw)¶Subtype of RemovedIn20Warning to indicate an API that moved only.
sqlalchemy.exc.
MultipleResultsFound
(*arg, **kw)¶A single database result was required but more than one were found.
Changed in version 1.4: This exception is now part of the
sqlalchemy.exc
module in Core, moved from the ORM. The symbol
remains importable from sqlalchemy.orm.exc
.
sqlalchemy.exc.
NoForeignKeysError
(*arg, **kw)¶Raised when no foreign keys can be located between two selectables during a join.
sqlalchemy.exc.
NoInspectionAvailable
(*arg, **kw)¶A subject passed to sqlalchemy.inspection.inspect()
produced
no context for inspection.
sqlalchemy.exc.
NoReferenceError
(*arg, **kw)¶Raised by ForeignKey
to indicate a reference cannot be resolved.
sqlalchemy.exc.
NoReferencedColumnError
(message, tname, cname)¶Raised by ForeignKey
when the referred Column
cannot be
located.
sqlalchemy.exc.
NoReferencedTableError
(message, tname)¶Raised by ForeignKey
when the referred Table
cannot be
located.
sqlalchemy.exc.
NoResultFound
(*arg, **kw)¶A database result was required but none was found.
Changed in version 1.4: This exception is now part of the
sqlalchemy.exc
module in Core, moved from the ORM. The symbol
remains importable from sqlalchemy.orm.exc
.
sqlalchemy.exc.
NoSuchColumnError
¶A nonexistent column is requested from a Row
.
sqlalchemy.exc.
NoSuchModuleError
(*arg, **kw)¶Raised when a dynamically-loaded module (usually a database dialect) of a particular name cannot be located.
sqlalchemy.exc.
NoSuchTableError
(*arg, **kw)¶Table does not exist or is not visible to a connection.
sqlalchemy.exc.
NotSupportedError
(statement, params, orig, hide_parameters=False, connection_invalidated=False, code=None, ismulti=None)¶Wraps a DB-API NotSupportedError.
sqlalchemy.exc.
ObjectNotExecutableError
(target)¶Raised when an object is passed to .execute() that can’t be executed as SQL.
New in version 1.1.
sqlalchemy.exc.
OperationalError
(statement, params, orig, hide_parameters=False, connection_invalidated=False, code=None, ismulti=None)¶Wraps a DB-API OperationalError.
sqlalchemy.exc.
PendingRollbackError
(*arg, **kw)¶A transaction has failed and needs to be rolled back before continuing.
New in version 1.4.
sqlalchemy.exc.
ProgrammingError
(statement, params, orig, hide_parameters=False, connection_invalidated=False, code=None, ismulti=None)¶Wraps a DB-API ProgrammingError.
sqlalchemy.exc.
RemovedIn20Warning
(*arg, **kw)¶Issued for usage of APIs specifically deprecated in SQLAlchemy 2.0.
sqlalchemy.exc.RemovedIn20Warning.
deprecated_since
= '1.4'¶Indicates the version that started raising this deprecation warning
sqlalchemy.exc.
ResourceClosedError
(*arg, **kw)¶An operation was requested from a connection, cursor, or other object that’s in a closed state.
sqlalchemy.exc.
SADeprecationWarning
(*arg, **kw)¶Issued for usage of deprecated APIs.
sqlalchemy.exc.SADeprecationWarning.
deprecated_since
= None¶Indicates the version that started raising this deprecation warning
sqlalchemy.exc.
SAPendingDeprecationWarning
¶A similar warning as SADeprecationWarning
, this warning
is not used in modern versions of SQLAlchemy.
sqlalchemy.exc.SAPendingDeprecationWarning.
deprecated_since
= None¶Indicates the version that started raising this deprecation warning
sqlalchemy.exc.
SAWarning
(*arg, **kw)¶Issued at runtime.
sqlalchemy.exc.
SQLAlchemyError
(*arg, **kw)¶Generic error class.
sqlalchemy.exc.
StatementError
(message, statement, params, orig, hide_parameters=False, code=None, ismulti=None)¶An error occurred during execution of a SQL statement.
StatementError
wraps the exception raised
during execution, and features statement
and params
attributes which supply context regarding
the specifics of the statement which had an issue.
The wrapped exception object is available in
the orig
attribute.
sqlalchemy.exc.StatementError.
orig
= None¶The DBAPI exception object.
sqlalchemy.exc.StatementError.
params
= None¶The parameter list being used when this exception occurred.
sqlalchemy.exc.StatementError.
statement
= None¶The string SQL statement being invoked when this exception occurred.
sqlalchemy.exc.
TimeoutError
(*arg, **kw)¶Raised when a connection pool times out on getting a connection.
sqlalchemy.exc.
UnboundExecutionError
(*arg, **kw)¶SQL was attempted without a database connection to execute it on.
sqlalchemy.exc.
UnreflectableTableError
(*arg, **kw)¶Table exists but can’t be reflected for some reason.
New in version 1.2.
sqlalchemy.exc.
UnsupportedCompilationError
(compiler, element_type, message=None)¶Raised when an operation is not supported by the given compiler.
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