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¶

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

Class signature

class sqlalchemy.exc.AmbiguousForeignKeysError (sqlalchemy.exc.ArgumentError)

exceptionsqlalchemy.exc.ArgumentError¶

Raised when an invalid or conflicting function argument is supplied.

This error generally corresponds to construction time state errors.

Class signature

class sqlalchemy.exc.ArgumentError (sqlalchemy.exc.SQLAlchemyError)

exceptionsqlalchemy.exc.AwaitRequired¶

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

Class signature

class sqlalchemy.exc.AwaitRequired (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.Base20DeprecationWarning¶

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

Class signature

class sqlalchemy.exc.Base20DeprecationWarning (sqlalchemy.exc.SADeprecationWarning)

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

Indicates the version that started raising this deprecation warning

exceptionsqlalchemy.exc.CircularDependencyError¶

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.

Class signature

class sqlalchemy.exc.CircularDependencyError (sqlalchemy.exc.SQLAlchemyError)

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

exceptionsqlalchemy.exc.CompileError¶

Raised when an error occurs during SQL compilation

Class signature

class sqlalchemy.exc.CompileError (sqlalchemy.exc.SQLAlchemyError)

exceptionsqlalchemy.exc.ConstraintColumnNotFoundError¶

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

Added in version 2.0.

Class signature

class sqlalchemy.exc.ConstraintColumnNotFoundError (sqlalchemy.exc.ArgumentError)

exceptionsqlalchemy.exc.DBAPIError¶

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.

Class signature

class sqlalchemy.exc.DBAPIError (sqlalchemy.exc.StatementError)

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)¶

exceptionsqlalchemy.exc.DataError¶

Wraps a DB-API DataError.

Class signature

class sqlalchemy.exc.DataError (sqlalchemy.exc.DatabaseError)

exceptionsqlalchemy.exc.DatabaseError¶

Wraps a DB-API DatabaseError.

Class signature

class sqlalchemy.exc.DatabaseError (sqlalchemy.exc.DBAPIError)

exceptionsqlalchemy.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 raises InvalidRequestError regarding the connection attempt.

Class signature

class sqlalchemy.exc.DisconnectionError (sqlalchemy.exc.SQLAlchemyError)

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¶

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.

Class signature

class sqlalchemy.exc.DuplicateColumnError (sqlalchemy.exc.ArgumentError)

classsqlalchemy.exc.HasDescriptionCode¶

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

exceptionsqlalchemy.exc.IdentifierError¶

Raised when a schema name is beyond the max character limit

Class signature

class sqlalchemy.exc.IdentifierError (sqlalchemy.exc.SQLAlchemyError)

exceptionsqlalchemy.exc.IllegalStateChangeError¶

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

Added in version 2.0.

Class signature

class sqlalchemy.exc.IllegalStateChangeError (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.IntegrityError¶

Wraps a DB-API IntegrityError.

Class signature

class sqlalchemy.exc.IntegrityError (sqlalchemy.exc.DatabaseError)

exceptionsqlalchemy.exc.InterfaceError¶

Wraps a DB-API InterfaceError.

Class signature

class sqlalchemy.exc.InterfaceError (sqlalchemy.exc.DBAPIError)

exceptionsqlalchemy.exc.InternalError¶

Wraps a DB-API InternalError.

Class signature

class sqlalchemy.exc.InternalError (sqlalchemy.exc.DatabaseError)

exceptionsqlalchemy.exc.InvalidRequestError¶

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

This error generally corresponds to runtime state errors.

Class signature

class sqlalchemy.exc.InvalidRequestError (sqlalchemy.exc.SQLAlchemyError)

exceptionsqlalchemy.exc.InvalidatePoolError¶

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.

Added in version 1.2.

Class signature

class sqlalchemy.exc.InvalidatePoolError (sqlalchemy.exc.DisconnectionError)

exceptionsqlalchemy.exc.LegacyAPIWarning¶

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

Class signature

class sqlalchemy.exc.LegacyAPIWarning (sqlalchemy.exc.Base20DeprecationWarning)

exceptionsqlalchemy.exc.MissingGreenlet¶

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

Class signature

class sqlalchemy.exc.MissingGreenlet (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.MovedIn20Warning¶

Subtype of RemovedIn20Warning to indicate an API that moved only.

Class signature

class sqlalchemy.exc.MovedIn20Warning (sqlalchemy.exc.Base20DeprecationWarning)

exceptionsqlalchemy.exc.MultipleResultsFound¶

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.

Class signature

class sqlalchemy.exc.MultipleResultsFound (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.NoForeignKeysError¶

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

Class signature

class sqlalchemy.exc.NoForeignKeysError (sqlalchemy.exc.ArgumentError)

exceptionsqlalchemy.exc.NoInspectionAvailable¶

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

Class signature

class sqlalchemy.exc.NoInspectionAvailable (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.NoReferenceError¶

Raised by ForeignKey to indicate a reference cannot be resolved.

Class signature

class sqlalchemy.exc.NoReferenceError (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.NoReferencedColumnError¶

Raised by ForeignKey when the referred Column cannot be located.

Class signature

class sqlalchemy.exc.NoReferencedColumnError (sqlalchemy.exc.NoReferenceError)

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

exceptionsqlalchemy.exc.NoReferencedTableError¶

Raised by ForeignKey when the referred Table cannot be located.

Class signature

class sqlalchemy.exc.NoReferencedTableError (sqlalchemy.exc.NoReferenceError)

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

exceptionsqlalchemy.exc.NoResultFound¶

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.

Class signature

class sqlalchemy.exc.NoResultFound (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.NoSuchColumnError¶

A nonexistent column is requested from a Row.

Class signature

class sqlalchemy.exc.NoSuchColumnError (sqlalchemy.exc.InvalidRequestError, builtins.KeyError)

exceptionsqlalchemy.exc.NoSuchModuleError¶

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

Class signature

class sqlalchemy.exc.NoSuchModuleError (sqlalchemy.exc.ArgumentError)

exceptionsqlalchemy.exc.NoSuchTableError¶

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

Class signature

class sqlalchemy.exc.NoSuchTableError (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.NotSupportedError¶

Wraps a DB-API NotSupportedError.

Class signature

class sqlalchemy.exc.NotSupportedError (sqlalchemy.exc.DatabaseError)

exceptionsqlalchemy.exc.ObjectNotExecutableError¶

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

Class signature

class sqlalchemy.exc.ObjectNotExecutableError (sqlalchemy.exc.ArgumentError)

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

exceptionsqlalchemy.exc.OperationalError¶

Wraps a DB-API OperationalError.

Class signature

class sqlalchemy.exc.OperationalError (sqlalchemy.exc.DatabaseError)

exceptionsqlalchemy.exc.PendingRollbackError¶

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

Added in version 1.4.

Class signature

class sqlalchemy.exc.PendingRollbackError (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.ProgrammingError¶

Wraps a DB-API ProgrammingError.

Class signature

class sqlalchemy.exc.ProgrammingError (sqlalchemy.exc.DatabaseError)

exceptionsqlalchemy.exc.ResourceClosedError¶

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

Class signature

class sqlalchemy.exc.ResourceClosedError (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.SADeprecationWarning¶

Issued for usage of deprecated APIs.

Class signature

class sqlalchemy.exc.SADeprecationWarning (sqlalchemy.exc.HasDescriptionCode, builtins.DeprecationWarning)

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

Indicates the version that started raising this deprecation warning

exceptionsqlalchemy.exc.SAPendingDeprecationWarning¶

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

Class signature

class sqlalchemy.exc.SAPendingDeprecationWarning (builtins.PendingDeprecationWarning)

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

Indicates the version that started raising this deprecation warning

exceptionsqlalchemy.exc.SATestSuiteWarning¶

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.

Class signature

class sqlalchemy.exc.SATestSuiteWarning (builtins.Warning)

exceptionsqlalchemy.exc.SAWarning¶

Issued at runtime.

Class signature

class sqlalchemy.exc.SAWarning (sqlalchemy.exc.HasDescriptionCode, builtins.RuntimeWarning)

exceptionsqlalchemy.exc.SQLAlchemyError¶

Generic error class.

Class signature

class sqlalchemy.exc.SQLAlchemyError (sqlalchemy.exc.HasDescriptionCode, builtins.Exception)

exceptionsqlalchemy.exc.StatementError¶

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.

Class signature

class sqlalchemy.exc.StatementError (sqlalchemy.exc.SQLAlchemyError)

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.

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¶

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

Class signature

class sqlalchemy.exc.TimeoutError (sqlalchemy.exc.SQLAlchemyError)

exceptionsqlalchemy.exc.UnboundExecutionError¶

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

Class signature

class sqlalchemy.exc.UnboundExecutionError (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.UnreflectableTableError¶

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

Added in version 1.2.

Class signature

class sqlalchemy.exc.UnreflectableTableError (sqlalchemy.exc.InvalidRequestError)

exceptionsqlalchemy.exc.UnsupportedCompilationError¶

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>

Class signature

class sqlalchemy.exc.UnsupportedCompilationError (sqlalchemy.exc.CompileError)

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