class ExceptionContextImpl(ExceptionContext):
.ExceptionContext interface.| Method | __init__ |
Undocumented |
| Instance Variable | connection |
The _engine.Connection in use during the exception. |
| Instance Variable | engine |
The _engine.Engine in use during the exception. |
| Instance Variable | execution_context |
The .ExecutionContext corresponding to the execution operation in progress. |
| Instance Variable | invalidate_pool_on_disconnect |
Represent whether all connections in the pool should be invalidated when a "disconnect" condition is in effect. |
| Instance Variable | is_disconnect |
Represent whether the exception as occurred represents a "disconnect" condition. |
| Instance Variable | original_exception |
The exception object which was caught. |
| Instance Variable | parameters |
Parameter collection that was emitted directly to the DBAPI. |
| Instance Variable | sqlalchemy_exception |
The sqlalchemy.exc.StatementError which wraps the original, and will be raised if exception handling is not circumvented by the event. |
| Instance Variable | statement |
String SQL statement that was emitted directly to the DBAPI. |
Inherited from ExceptionContext:
| Class Variable | chained_exception |
The exception that was returned by the previous handler in the exception chain, if any. |
| Class Variable | cursor |
The DBAPI cursor object. |
Undocumented
The _engine.Connection in use during the exception.
This member is present, except in the case of a failure when first connecting.
See Also
.ExceptionContext.engine
The _engine.Engine in use during the exception.
This member should always be present, even in the case of a failure when first connecting.
The .ExecutionContext corresponding to the execution
operation in progress.
This is present for statement execution operations, but not for
operations such as transaction begin/end. It also is not present when
the exception was raised before the .ExecutionContext
could be constructed.
Note that the .ExceptionContext.statement and
.ExceptionContext.parameters members may represent a
different value than that of the .ExecutionContext,
potentially in the case where a
_events.ConnectionEvents.before_cursor_execute event or similar
modified the statement/parameters to be sent.
May be None.
Represent whether all connections in the pool should be invalidated when a "disconnect" condition is in effect.
Setting this flag to False within the scope of the
_events.ConnectionEvents.handle_error
event will have the effect such
that the full collection of connections in the pool will not be
invalidated during a disconnect; only the current connection that is the
subject of the error will actually be invalidated.
The purpose of this flag is for custom disconnect-handling schemes where the invalidation of other connections in the pool is to be performed based on other conditions, or even on a per-connection basis.
Represent whether the exception as occurred represents a "disconnect" condition.
This flag will always be True or False within the scope of the
_events.ConnectionEvents.handle_error handler.
SQLAlchemy will defer to this flag in order to determine whether or not the connection should be invalidated subsequently. That is, by assigning to this flag, a "disconnect" event which then results in a connection and pool invalidation can be invoked or prevented by changing this flag.
Note
The pool "pre_ping" handler enabled using the :paramref:`_sa.create_engine.pool_pre_ping` parameter does not consult this event before deciding if the "ping" returned false, as opposed to receiving an unhandled error. For this use case, the :ref:`legacy recipe based on engine_connect() may be used <pool_disconnects_pessimistic_custom>`. A future API allow more comprehensive customization of the "disconnect" detection mechanism across all functions.
The sqlalchemy.exc.StatementError which wraps the original,
and will be raised if exception handling is not circumvented by the event.
May be None, as not all exception types are wrapped by SQLAlchemy. For DBAPI-level exceptions that subclass the dbapi's Error class, this field will always be present.