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.

exceptionsqlalchemy.exc.AmbiguousForeignKeysError¶

inherits from sqlalchemy.exc.ArgumentError

Raised when more than one foreign key matching can be located between two selectables during a join.

exceptionsqlalchemy.exc.ArgumentError¶

inherits from sqlalchemy.exc.SQLAlchemyError

Raised when an invalid or conflicting function argument is supplied.

This error generally corresponds to construction time state errors.

exceptionsqlalchemy.exc.AwaitRequired¶

inherits from sqlalchemy.exc.InvalidRequestError

Error raised by the async greenlet spawn if no async operation was awaited when it required one.

exceptionsqlalchemy.exc.Base20DeprecationWarning¶

inherits from sqlalchemy.exc.SADeprecationWarning

Issued for usage of APIs specifically deprecated or legacy in SQLAlchemy 2.0.

See also

The <some function> in SQLAlchemy 2.0 will no longer <something>.

SQLAlchemy 2.0 Deprecations Mode

attribute sqlalchemy.exc.Base20DeprecationWarning. deprecated_since:str|None='1.4'¶

Indicates the version that started raising this deprecation warning

exceptionsqlalchemy.exc.CircularDependencyError¶

inherits from sqlalchemy.exc.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 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.

method sqlalchemy.exc.CircularDependencyError. __init__(message:str, cycles:Any, edges:Any, msg:str|None=None, code:str|None=None)¶

exceptionsqlalchemy.exc.CompileError¶

inherits from sqlalchemy.exc.SQLAlchemyError

Raised when an error occurs during SQL compilation

exceptionsqlalchemy.exc.ConstraintColumnNotFoundError¶

inherits from sqlalchemy.exc.ArgumentError

raised when a constraint refers to a string column name that is not present in the table being constrained.

Added in version 2.0.

exceptionsqlalchemy.exc.DBAPIError¶

inherits from sqlalchemy.exc.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 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.

method sqlalchemy.exc.DBAPIError. __init__(statement:str|None, params:_AnyExecuteParams|None, orig:BaseException, hide_parameters:bool=False, connection_invalidated:bool=False, code:str|None=None, ismulti:bool|None=None)¶

attribute sqlalchemy.exc.DBAPIError. driver_exception¶

The exception object originating from the driver (DBAPI) outside of SQLAlchemy.

In the case of some asyncio dialects, special steps are taken to resolve the exception to what the third party driver has raised, even for SQLAlchemy dialects that include an "emulated" DBAPI exception hierarchy.

For non-asyncio dialects, this attribute will be the same attribute as the StatementError.orig attribute.

For an asyncio dialect provided by SQLAlchemy, depending on if the dialect provides an "emulated" exception hierarchy or if the underlying DBAPI raises DBAPI-style exceptions, it will refer to either the EmulatedDBAPIException.driver_exception attribute on the EmulatedDBAPIException that’s thrown (such as when using asyncpg), or to the actual exception object thrown by the third party driver.

Added in version 2.1.

exceptionsqlalchemy.exc.DataError¶

inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API DataError.

exceptionsqlalchemy.exc.DatabaseError¶

inherits from sqlalchemy.exc.DBAPIError

Wraps a DB-API DatabaseError.

exceptionsqlalchemy.exc.DisconnectionError¶

inherits from sqlalchemy.exc.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 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.

classsqlalchemy.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.:

fromsqlalchemy.excimport DontWrapMixin
classMyCustomException(Exception, DontWrapMixin):
 pass
classMySpecialType(TypeDecorator):
 impl = String
 defprocess_bind_param(self, value, dialect):
 if value == "invalid":
 raise MyCustomException("invalid!")

exceptionsqlalchemy.exc.DuplicateColumnError¶

inherits from sqlalchemy.exc.ArgumentError

a Column is being added to a Table that would replace another Column, without appropriate parameters to allow this in place.

Added in version 2.0.0b4.

exceptionsqlalchemy.exc.EmulatedDBAPIException¶

inherits from builtins.Exception

Serves as the base of the DBAPI Error class for dialects where a DBAPI exception hierrchy needs to be emulated.

The current example is the asyncpg dialect.

Added in version 2.1.

method sqlalchemy.exc.EmulatedDBAPIException. __init__(message:str, orig:Exception|None=None)¶

attribute sqlalchemy.exc.EmulatedDBAPIException. driver_exception¶

The original driver exception that was raised.

This exception object will always originate from outside of SQLAlchemy.

classsqlalchemy.exc.HasDescriptionCode¶

helper which adds ‘code’ as an attribute and ‘_code_str’ as a method

exceptionsqlalchemy.exc.IdentifierError¶

inherits from sqlalchemy.exc.SQLAlchemyError

Raised when a schema name is beyond the max character limit

exceptionsqlalchemy.exc.IllegalStateChangeError¶

inherits from sqlalchemy.exc.InvalidRequestError

An object that tracks state encountered an illegal state change of some kind.

Added in version 2.0.

exceptionsqlalchemy.exc.IntegrityError¶

inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API IntegrityError.

exceptionsqlalchemy.exc.InterfaceError¶

inherits from sqlalchemy.exc.DBAPIError

Wraps a DB-API InterfaceError.

exceptionsqlalchemy.exc.InternalError¶

inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API InternalError.

exceptionsqlalchemy.exc.InvalidRequestError¶

inherits from sqlalchemy.exc.SQLAlchemyError

SQLAlchemy was asked to do something it can’t do.

This error generally corresponds to runtime state errors.

exceptionsqlalchemy.exc.InvalidatePoolError¶

inherits from sqlalchemy.exc.DisconnectionError

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.

exceptionsqlalchemy.exc.LegacyAPIWarning¶

inherits from sqlalchemy.exc.Base20DeprecationWarning

indicates an API that is in ‘legacy’ status, a long term deprecation.

exceptionsqlalchemy.exc.MissingGreenlet¶

inherits from sqlalchemy.exc.InvalidRequestError

Error raised by the async greenlet await_ if called while not inside the greenlet spawn context.

exceptionsqlalchemy.exc.MovedIn20Warning¶

inherits from sqlalchemy.exc.Base20DeprecationWarning

Subtype of Base20DeprecationWarning to indicate an API that moved only.

exceptionsqlalchemy.exc.MultipleResultsFound¶

inherits from sqlalchemy.exc.InvalidRequestError

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.

exceptionsqlalchemy.exc.NoForeignKeysError¶

inherits from sqlalchemy.exc.ArgumentError

Raised when no foreign keys can be located between two selectables during a join.

exceptionsqlalchemy.exc.NoInspectionAvailable¶

inherits from sqlalchemy.exc.InvalidRequestError

A subject passed to sqlalchemy.inspection.inspect() produced no context for inspection.

exceptionsqlalchemy.exc.NoReferenceError¶

inherits from sqlalchemy.exc.InvalidRequestError

Raised by ForeignKey to indicate a reference cannot be resolved.

exceptionsqlalchemy.exc.NoReferencedColumnError¶

inherits from sqlalchemy.exc.NoReferenceError

Raised by ForeignKey when the referred Column cannot be located.

method sqlalchemy.exc.NoReferencedColumnError. __init__(message:str, tname:str, cname:str)¶

exceptionsqlalchemy.exc.NoReferencedTableError¶

inherits from sqlalchemy.exc.NoReferenceError

Raised by ForeignKey when the referred Table cannot be located.

method sqlalchemy.exc.NoReferencedTableError. __init__(message:str, tname:str)¶

exceptionsqlalchemy.exc.NoResultFound¶

inherits from sqlalchemy.exc.InvalidRequestError

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.

exceptionsqlalchemy.exc.NoSuchColumnError¶

inherits from sqlalchemy.exc.InvalidRequestError, builtins.KeyError

A nonexistent column is requested from a Row.

exceptionsqlalchemy.exc.NoSuchModuleError¶

inherits from sqlalchemy.exc.ArgumentError

Raised when a dynamically-loaded module (usually a database dialect) of a particular name cannot be located.

exceptionsqlalchemy.exc.NoSuchTableError¶

inherits from sqlalchemy.exc.InvalidRequestError

Table does not exist or is not visible to a connection.

exceptionsqlalchemy.exc.NotSupportedError¶

inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API NotSupportedError.

exceptionsqlalchemy.exc.ObjectNotExecutableError¶

inherits from sqlalchemy.exc.ArgumentError

Raised when an object is passed to .execute() that can’t be executed as SQL.

method sqlalchemy.exc.ObjectNotExecutableError. __init__(target:Any)¶

exceptionsqlalchemy.exc.OperationalError¶

inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API OperationalError.

exceptionsqlalchemy.exc.PendingRollbackError¶

inherits from sqlalchemy.exc.InvalidRequestError

A transaction has failed and needs to be rolled back before continuing.

Added in version 1.4.

exceptionsqlalchemy.exc.ProgrammingError¶

inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API ProgrammingError.

exceptionsqlalchemy.exc.ResourceClosedError¶

inherits from sqlalchemy.exc.InvalidRequestError

An operation was requested from a connection, cursor, or other object that’s in a closed state.

exceptionsqlalchemy.exc.SADeprecationWarning¶

inherits from sqlalchemy.exc.HasDescriptionCode, builtins.DeprecationWarning

Issued for usage of deprecated APIs.

attribute sqlalchemy.exc.SADeprecationWarning. deprecated_since:str|None=None¶

Indicates the version that started raising this deprecation warning

exceptionsqlalchemy.exc.SAPendingDeprecationWarning¶

inherits from builtins.PendingDeprecationWarning

A similar warning as SADeprecationWarning, this warning is not used in modern versions of SQLAlchemy.

attribute sqlalchemy.exc.SAPendingDeprecationWarning. deprecated_since:str|None=None¶

Indicates the version that started raising this deprecation warning

exceptionsqlalchemy.exc.SATestSuiteWarning¶

inherits from builtins.Warning

warning for a condition detected during tests that is non-fatal

Currently outside of SAWarning so that we can work around tools like Alembic doing the wrong thing with warnings.

exceptionsqlalchemy.exc.SAWarning¶

inherits from sqlalchemy.exc.HasDescriptionCode, builtins.RuntimeWarning

Issued at runtime.

exceptionsqlalchemy.exc.SQLAlchemyError¶

inherits from sqlalchemy.exc.HasDescriptionCode, builtins.Exception

Generic error class.

exceptionsqlalchemy.exc.StatementError¶

inherits from sqlalchemy.exc.SQLAlchemyError

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.

method sqlalchemy.exc.StatementError. __init__(message:str, statement:str|None, params:_AnyExecuteParams|None, orig:BaseException|None, hide_parameters:bool=False, code:str|None=None, ismulti:bool|None=None)¶

attribute sqlalchemy.exc.StatementError. ismulti:bool|None=None¶

multi parameter passed to repr_params(). None is meaningful.

attribute sqlalchemy.exc.StatementError. orig:BaseException|None=None¶

The original exception that was thrown.

See also

DBAPIError.driver_exception - a more specific attribute that is guaranteed to return the exception object raised by the third party driver in use, even when using asyncio.

attribute sqlalchemy.exc.StatementError. params:_AnyExecuteParams|None=None¶

The parameter list being used when this exception occurred.

attribute sqlalchemy.exc.StatementError. statement:str|None=None¶

The string SQL statement being invoked when this exception occurred.

exceptionsqlalchemy.exc.TimeoutError¶

inherits from sqlalchemy.exc.SQLAlchemyError

Raised when a connection pool times out on getting a connection.

exceptionsqlalchemy.exc.UnboundExecutionError¶

inherits from sqlalchemy.exc.InvalidRequestError

SQL was attempted without a database connection to execute it on.

exceptionsqlalchemy.exc.UnreflectableTableError¶

inherits from sqlalchemy.exc.InvalidRequestError

Table exists but can’t be reflected for some reason.

exceptionsqlalchemy.exc.UnsupportedCompilationError¶

inherits from sqlalchemy.exc.CompileError

Raised when an operation is not supported by the given compiler.

See also

How do I render SQL expressions as strings, possibly with bound parameters inlined?

Compiler StrSQLCompiler can’t render element of type <element type>

method sqlalchemy.exc.UnsupportedCompilationError. __init__(compiler:Compiled |TypeCompiler, element_type:Type[ClauseElement ], message:str|None=None)¶