Errors, Notices, and Notifications

Messages for errors, warnings, async notifications, and runtime parameter changes.

Message	Direction	Description
ErrorResponse	Backend	Error with severity, code, message
NoticeResponse	Backend	Warning or informational notice
NotificationResponse	Backend	LISTEN/NOTIFY notification
ParameterStatus	Backend	Runtime parameter changed

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ErrorResponse

Field	Type	Description
fields	dict[str, str]	Error fields keyed by single-char code

Common field keys:

Key	Meaning
S	Severity (ERROR, FATAL, WARNING, etc.)
V	Severity (non-localized)
C	SQLSTATE error code
M	Message text
D	Detail
H	Hint

Convenience properties: severity, code, message.

from pygwire.messages import ErrorResponse

if isinstance(msg, ErrorResponse):
    print(f"{msg.severity}: {msg.message} [{msg.code}]")
    # Or access fields directly
    print(msg.fields.get("D"))  # Detail

NoticeResponse

Same structure as ErrorResponse. Used for warnings and informational notices that do not terminate the current operation.

Field	Type	Description
fields	dict[str, str]	Notice fields keyed by single-char code

Convenience properties: severity, code, message.

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NotificationResponse

Delivered asynchronously when another session sends a NOTIFY on a channel you are LISTENing to. Can arrive at any time during an active connection.

Field	Type	Description
process_id	int	Notifying backend PID
channel	str	Channel name
payload	str	Notification payload

ParameterStatus

Sent by the server when a runtime parameter changes (e.g. server_version, client_encoding). Also sent during the initialization phase after authentication.

Field	Type	Description
name	str	Parameter name
value	str	Parameter value