SQLAlchemy 1.1 Documentation
Core Exceptions¶
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
.
-
exception
sqlalchemy.exc.
AmbiguousForeignKeysError
¶ Raised when more than one foreign key matching can be located between two selectables during a join.
-
exception
sqlalchemy.exc.
ArgumentError
¶ Raised when an invalid or conflicting function argument is supplied.
This error generally corresponds to construction time state errors.
-
exception
sqlalchemy.exc.
CircularDependencyError
(message, cycles, edges, msg=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, twoForeignKey
orForeignKeyConstraint
objects mutually refer to each other. Apply theuse_alter=True
flag to one or both, see Creating/Dropping Foreign Key Constraints via ALTER.
- 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
-
exception
sqlalchemy.exc.
CompileError
¶ Raised when an error occurs during SQL compilation
-
exception
sqlalchemy.exc.
DBAPIError
(statement, params, orig, connection_invalidated=False)¶ 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’sError
type maps toDBAPIError
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
featuresstatement
andparams
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
orig
attribute. Its type and properties are DB-API implementation specific.
-
exception
sqlalchemy.exc.
DataError
(statement, params, orig, connection_invalidated=False)¶ Wraps a DB-API DataError.
-
exception
sqlalchemy.exc.
DatabaseError
(statement, params, orig, connection_invalidated=False)¶ Wraps a DB-API DatabaseError.
-
exception
sqlalchemy.exc.
DisconnectionError
¶ 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 raisesInvalidRequestError
regarding the connection attempt.
-
class
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!")
-
exception
sqlalchemy.exc.
IdentifierError
¶ Raised when a schema name is beyond the max character limit
-
exception
sqlalchemy.exc.
IntegrityError
(statement, params, orig, connection_invalidated=False)¶ Wraps a DB-API IntegrityError.
-
exception
sqlalchemy.exc.
InterfaceError
(statement, params, orig, connection_invalidated=False)¶ Wraps a DB-API InterfaceError.
-
exception
sqlalchemy.exc.
InternalError
(statement, params, orig, connection_invalidated=False)¶ Wraps a DB-API InternalError.
-
exception
sqlalchemy.exc.
InvalidRequestError
¶ SQLAlchemy was asked to do something it can’t do.
This error generally corresponds to runtime state errors.
-
exception
sqlalchemy.exc.
NoForeignKeysError
¶ Raised when no foreign keys can be located between two selectables during a join.
-
exception
sqlalchemy.exc.
NoInspectionAvailable
¶ A subject passed to
sqlalchemy.inspection.inspect()
produced no context for inspection.
-
exception
sqlalchemy.exc.
NoReferenceError
¶ Raised by
ForeignKey
to indicate a reference cannot be resolved.
-
exception
sqlalchemy.exc.
NoReferencedColumnError
(message, tname, cname)¶ Raised by
ForeignKey
when the referredColumn
cannot be located.
-
exception
sqlalchemy.exc.
NoReferencedTableError
(message, tname)¶ Raised by
ForeignKey
when the referredTable
cannot be located.
-
exception
sqlalchemy.exc.
NoSuchColumnError
¶ A nonexistent column is requested from a
RowProxy
.
-
exception
sqlalchemy.exc.
NoSuchModuleError
¶ Raised when a dynamically-loaded module (usually a database dialect) of a particular name cannot be located.
-
exception
sqlalchemy.exc.
NoSuchTableError
¶ Table does not exist or is not visible to a connection.
-
exception
sqlalchemy.exc.
NotSupportedError
(statement, params, orig, connection_invalidated=False)¶ Wraps a DB-API NotSupportedError.
-
exception
sqlalchemy.exc.
OperationalError
(statement, params, orig, connection_invalidated=False)¶ Wraps a DB-API OperationalError.
-
exception
sqlalchemy.exc.
ProgrammingError
(statement, params, orig, connection_invalidated=False)¶ Wraps a DB-API ProgrammingError.
-
exception
sqlalchemy.exc.
ResourceClosedError
¶ An operation was requested from a connection, cursor, or other object that’s in a closed state.
-
exception
sqlalchemy.exc.
SADeprecationWarning
¶ Issued once per usage of a deprecated API.
-
exception
sqlalchemy.exc.
SAPendingDeprecationWarning
¶ Issued once per usage of a deprecated API.
-
exception
sqlalchemy.exc.
SAWarning
¶ Issued at runtime.
-
exception
sqlalchemy.exc.
SQLAlchemyError
¶ Generic error class.
-
exception
sqlalchemy.exc.
StatementError
(message, statement, params, orig)¶ An error occurred during execution of a SQL statement.
StatementError
wraps the exception raised during execution, and featuresstatement
andparams
attributes which supply context regarding the specifics of the statement which had an issue.The wrapped exception object is available in the
orig
attribute.-
orig
= None¶ The DBAPI exception object.
-
params
= None¶ The parameter list being used when this exception occurred.
-
statement
= None¶ The string SQL statement being invoked when this exception occurred.
-
-
exception
sqlalchemy.exc.
TimeoutError
¶ Raised when a connection pool times out on getting a connection.
-
exception
sqlalchemy.exc.
UnboundExecutionError
¶ SQL was attempted without a database connection to execute it on.
-
exception
sqlalchemy.exc.
UnsupportedCompilationError
(compiler, element_type)¶ Raised when an operation is not supported by the given compiler.
버전 0.8.3에 추가.