如何使用IF / ELSE语句在Sql中更新或创建新的xml节点条目

Example:

<root>
    <StartOne>
        <Value1>Lopez, Michelle MD</Value1>
        <Value2>Spanish</Value2>
        <Value3>
            <a title="49 west point" href="/go.html?url=myloc.aspx?id=56" target="_blank">49 west point</a>
        </Value3>
        <Value4>908-783-0909</Value4>
        <Value5>
            <a title="CM" href="/go.html?url=myspec.aspx?id=78" target="_blank">CM</a>
        </Value5>
        <Value6 /> /* No anchor link exist, but I would like to add the same format as Value5 */
    </StartOne>
</root>
<root>
    <StartOne>
        <Value