src/Table.php
public function primary()
    {
        foreach ($this->columns() as $column) {
            $primary = $column->isPrimaryKey();

            $primary && $result = $column;
        }

        return isset($result) ? $result : null;
    }
public function primary()
    {
        foreach ($this->columns() as $column) {
            $primary = $column->isPrimaryKey();

            $primary && $result = $column;
        }

        return isset($result) ? $result : null;
    }
Returns the primary key of a table.

@return \Rougin\Describe\Column|null