SQLBuilder\Universal\Syntax\Column::buildDefaultClause PHP Метод

    public function buildDefaultClause(BaseDriver $driver)
    {
        $sql = '';
        // Build default value
        if (($default = $this->default) !== NULL) {
            // When user defines a closure, it means the default value is
            // lazily provided, don't build the closure value for SQL
            // statement.
            if (!is_callable($default) && !$default instanceof Closure) {
                $sql .= ' DEFAULT ' . $driver->deflate($default);
            }
        }
        if ($this->onUpdate && $driver instanceof MySQLDriver) {
            $sql .= ' ON UPDATE ' . $driver->deflate($this->onUpdate);
        }
        return $sql;
    }