public function update(array $data) : int
    {
        $table = $this->definition->getName();
        $columns = $this->definition->getFullColumns();
        $update = [];
        foreach ($data as $column => $value) {
            if (isset($columns[$column])) {
                $update[$column] = $this->normalizeValue($columns[$column], $value);
            }
        }
        if (!count($update)) {
            throw new DBException('No valid columns to update');
        }
        $sql = 'UPDATE '.$table.' SET ';
        $par = [];
        $sql .= implode(', ', array_map(function ($v) { return $v . ' = ?'; }, array_keys($update))) . ' ';
        $par = array_merge($par, array_values($update));
        if (count($this->where)) {
            $sql .= 'WHERE ';
            $tmp = [];
            foreach ($this->where as $v) {
                $tmp[] = $v[0];
                $par = array_merge($par, $v[1]);
            }
            $sql .= implode(' AND ', $tmp) . ' ';
        }
        if (count($this->order)) {
            $sql .= $this->order[0];
            $par = array_merge($par, $this->order[1]);
        }
        return $this->db->query($sql, $par)->affected();
    }