Method PartialUpdate

_examples/database/mysql/sql/service.go:163–212

PartialUpdate accepts a columns schema and a key-value map to update the record based on the given "id". Note: Trivial string, int and boolean type validations are performed here.

(ctx context.Context, id int64, schema map[string]reflect.Kind, attrs map[string]interface{})

// update the record based on the given "id".
// Note: Trivial string, int and boolean type validations are performed here.
func (s *Service) PartialUpdate(ctx context.Context, id int64, schema map[string]reflect.Kind, attrs map[string]interface{}) (int, error) {
	if len(schema) == 0 || len(attrs) == 0 {
		return 0, nil
	}

	var (
		keyLines []string
		values   []interface{}
	)

	for key, kind := range schema {
		v, ok := attrs[key]
		if !ok {
			continue
		}

		switch v.(type) {
		case string:
			if kind != reflect.String {
				return 0, ErrUnprocessable
			}
		case int:
			if kind != reflect.Int {
				return 0, ErrUnprocessable
			}
		case bool:
			if kind != reflect.Bool {
				return 0, ErrUnprocessable
			}
		}

		keyLines = append(keyLines, fmt.Sprintf("%s = ?", key))
		values = append(values, v)
	}

	if len(values) == 0 {
		return 0, nil
	}

	q := fmt.Sprintf("UPDATE %s SET %s WHERE %s = ?;",
		s.rec.TableName(), strings.Join(keyLines, ", "), s.rec.PrimaryKey())

	res, err := s.DB().Exec(ctx, q, append(values, id)...)
	if err != nil {
		return 0, err
	}

	n := GetAffectedRows(res)
	return n, nil
}

// GetAffectedRows returns the number of affected rows after
// a DELETE or UPDATE operation.