jackc/pgx · error

duplicate StructArgs key %q

Error message

duplicate StructArgs key %q

What it means

Error "duplicate StructArgs key %q" thrown in jackc/pgx.

Source

Thrown at named_args.go:112

	out := make(map[string]any, t.NumField())
	for i := 0; i < t.NumField(); i++ {
		sf := t.Field(i)

		// Ignore unexported fields.
		if sf.PkgPath != "" {
			continue
		}

		key, ok, err := dbTagKey(sf)
		if err != nil {
			return nil, err
		}
		if !ok {
			continue
		}

		if _, exists := out[key]; exists {
			return nil, fmt.Errorf("duplicate StructArgs key %q", key)
		}

		out[key] = v.Field(i).Interface()
	}

	return out, nil
}

// dbTagKey derives the named-argument key for a struct field. Tag parsing matches
// RowToStructByName* in rows.go (structTagKey, Lookup, comma options, db:"-").
// Anonymous embedded structs are skipped without flattening (unlike row scanning).
func dbTagKey(sf reflect.StructField) (key string, ok bool, err error) {
	if sf.Anonymous {
		ft := sf.Type
		if ft.Kind() == reflect.Pointer {
			ft = ft.Elem()
		}
		if ft.Kind() == reflect.Struct {

View on GitHub (pinned to ec1a0befd2)

When it happens

Trigger: Thrown at named_args.go:112 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/1fe58940d4dbf419.json. Report an issue: GitHub.