Watching queries

Subscribe to every query for logging or metrics. The callback receives the database, model, operation, SQL, parameters, duration, and row count. There is no cost when nothing is subscribed.

const off = db.$on('query', (e) => {
  if (e.duration_ms > 100) console.warn('slow query', e.sql, e.params);
});
db.$on('error', (e) => console.error(e.op, 'failed', e.error.message));
// off();  // stop listening

See more — docs/EVENTS.md for the full QueryEvent shape with semanticOp, custom sinks, sampling and privacy. docs/LOGGING.md for Pino/Winston wiring, redaction, request correlation. docs/TRACING.md for OpenTelemetry spans and W3C traceparent propagation. docs/METRICS.md for Prometheus histograms with cardinality discipline. docs/WATCH.md for Mongo change streams, Postgres LISTEN/NOTIFY, MySQL binlog tailing, and the WebSocket fan-out bridge for realtime UIs.

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