           <tr>
                <td><code>null</code></td>
                <td>Allow null?</td>
                <td>boolean</td>
                <td>No</td>
                <td><code>no</code></td>
                <td>
                </td>
            </tr>
            <tr>
                <td><code>primary</code></td>
                <td>Use as primary key?</td>
                <td>boolean</td>
                <td>No</td>
                <td></td>
                <td>
                </td>
            </t