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¶: inherits from sqlalchemy.exc.ArgumentError

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

exception sqlalchemy.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.

exception sqlalchemy.exc.AwaitRequired¶: inherits from sqlalchemy.exc.InvalidRequestError

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

exception sqlalchemy.exc.Base20DeprecationWarning¶

inherits from sqlalchemy.exc.SADeprecationWarning

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

SQLAlchemy 2.0 Deprecations Mode

attribute sqlalchemy.exc.Base20DeprecationWarning.deprecated_since: str | None = '1.4'¶: Indicates the version that started raising this deprecation warning

exception sqlalchemy.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)¶

exception sqlalchemy.exc.CompileError¶: inherits from sqlalchemy.exc.SQLAlchemyError

Raised when an error occurs during SQL compilation

exception sqlalchemy.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.

exception sqlalchemy.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)¶

exception sqlalchemy.exc.DataError¶: inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API DataError.

exception sqlalchemy.exc.DatabaseError¶: inherits from sqlalchemy.exc.DBAPIError

Wraps a DB-API DatabaseError.

exception sqlalchemy.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.

Object Name	Description
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.
HasDescriptionCode	helper which adds ‘code’ as an attribute and ‘_code_str’ as a method

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.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.

class sqlalchemy.exc.HasDescriptionCode¶: helper which adds ‘code’ as an attribute and ‘_code_str’ as a method

exception sqlalchemy.exc.IdentifierError¶: inherits from sqlalchemy.exc.SQLAlchemyError

Raised when a schema name is beyond the max character limit

exception sqlalchemy.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.

exception sqlalchemy.exc.IntegrityError¶: inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API IntegrityError.

exception sqlalchemy.exc.InterfaceError¶: inherits from sqlalchemy.exc.DBAPIError

Wraps a DB-API InterfaceError.

exception sqlalchemy.exc.InternalError¶: inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API InternalError.

exception sqlalchemy.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.

exception sqlalchemy.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.

Added in version 1.2.

exception sqlalchemy.exc.LegacyAPIWarning¶: inherits from sqlalchemy.exc.Base20DeprecationWarning

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

exception sqlalchemy.exc.MissingGreenlet¶: inherits from sqlalchemy.exc.InvalidRequestError

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

exception sqlalchemy.exc.MovedIn20Warning¶: inherits from sqlalchemy.exc.Base20DeprecationWarning

Subtype of RemovedIn20Warning to indicate an API that moved only.

exception sqlalchemy.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.

exception sqlalchemy.exc.NoForeignKeysError¶: inherits from sqlalchemy.exc.ArgumentError

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

exception sqlalchemy.exc.NoInspectionAvailable¶: inherits from sqlalchemy.exc.InvalidRequestError

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

exception sqlalchemy.exc.NoReferenceError¶: inherits from sqlalchemy.exc.InvalidRequestError

Raised by ForeignKey to indicate a reference cannot be resolved.

exception sqlalchemy.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)¶

exception sqlalchemy.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)¶

exception sqlalchemy.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.

exception sqlalchemy.exc.NoSuchColumnError¶: inherits from sqlalchemy.exc.InvalidRequestError, builtins.KeyError

A nonexistent column is requested from a Row.

exception sqlalchemy.exc.NoSuchModuleError¶: inherits from sqlalchemy.exc.ArgumentError

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

exception sqlalchemy.exc.NoSuchTableError¶: inherits from sqlalchemy.exc.InvalidRequestError

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

exception sqlalchemy.exc.NotSupportedError¶: inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API NotSupportedError.

exception sqlalchemy.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)¶

exception sqlalchemy.exc.OperationalError¶: inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API OperationalError.

exception sqlalchemy.exc.PendingRollbackError¶: inherits from sqlalchemy.exc.InvalidRequestError

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

Added in version 1.4.

exception sqlalchemy.exc.ProgrammingError¶: inherits from sqlalchemy.exc.DatabaseError

Wraps a DB-API ProgrammingError.

exception sqlalchemy.exc.ResourceClosedError¶: inherits from sqlalchemy.exc.InvalidRequestError

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

exception sqlalchemy.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

exception sqlalchemy.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

exception sqlalchemy.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.

exception sqlalchemy.exc.SAWarning¶: inherits from sqlalchemy.exc.HasDescriptionCode, builtins.RuntimeWarning

Issued at runtime.

exception sqlalchemy.exc.SQLAlchemyError¶: inherits from sqlalchemy.exc.HasDescriptionCode, builtins.Exception

Generic error class.

exception sqlalchemy.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.

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.

exception sqlalchemy.exc.TimeoutError¶: inherits from sqlalchemy.exc.SQLAlchemyError

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

exception sqlalchemy.exc.UnboundExecutionError¶: inherits from sqlalchemy.exc.InvalidRequestError

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

exception sqlalchemy.exc.UnreflectableTableError¶: inherits from sqlalchemy.exc.InvalidRequestError

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

Added in version 1.2.

exception sqlalchemy.exc.UnsupportedCompilationError¶

inherits from sqlalchemy.exc.CompileError

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

SQLAlchemy 2.0 Documentation

SQLAlchemy 2.0 Documentation

SQLAlchemy Core

Project Versions

Core Exceptions¶