number of field descriptions must equal number of destinatio

Error message

number of field descriptions must equal number of destinations, got %d and %d

What it means

Error "number of field descriptions must equal number of destinations, got %d and %d" thrown in jackc/pgx.

Source

Thrown at rows.go:257

	if len(fieldDescriptions) != len(values) {
		err := fmt.Errorf("number of field descriptions must equal number of values, got %d and %d", len(fieldDescriptions), len(values))
		rows.fatal(err)
		return err
	}

	if len(dest) == 1 {
		if rc, ok := dest[0].(RowScanner); ok {
			err := rc.ScanRow(rows)
			if err != nil {
				rows.fatal(err)
			}
			return err
		}
	}

	if len(fieldDescriptions) != len(dest) {
		err := fmt.Errorf("number of field descriptions must equal number of destinations, got %d and %d", len(fieldDescriptions), len(dest))
		rows.fatal(err)
		return err
	}

	if rows.scanPlans == nil {
		rows.scanPlans = make([]pgtype.ScanPlan, len(values))
		rows.scanTypes = make([]reflect.Type, len(values))
		for i := range dest {
			rows.scanPlans[i] = m.PlanScan(fieldDescriptions[i].DataTypeOID, fieldDescriptions[i].Format, dest[i])
			rows.scanTypes[i] = reflect.TypeOf(dest[i])
		}
	}

	for i, dst := range dest {
		if dst == nil {
			continue
		}

View on GitHub (pinned to ec1a0befd2)

When it happens

Trigger: Thrown at rows.go:257 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of jackc/pgx@ec1a0befd2 (2026-08-04). Data as JSON: /data/errors/4b122cf43ec1b575.json. Report an issue: GitHub.