TSQL for xml path - How can I include a subquery container element even if the subquery is empty?

Question

My query to build XML includes subqueries. The child records are supposed to go into a container element. The XML must have the container element even if there are no child records.

Consider the following. The <Patients> container element must exist even if there are no child records or validation fails.

<Hospital>
    <Patients>
        <Patient></Patient>
        <Patient></Patient>
        <Patient></Patient>
    </Patients>
</Hospital>

I've tried a couple of different approaches using FOR XML PATH:

select
    (
        select
            PatientFields
        from
            PatientTable
        for xml path('Patient'), root('Patients'), elements xsinil, type
    )
for xml path('Hospital'), elements xsinil, type

The above approach leaves out the <Patients> element altogether for an empty set.

The one below includes the tag but adds the xsi:nil="true" attribute, which also causes validation to fail.

select
    (
        select
            PatientFields
        from
            PatientTable
        for xml path('Patient'), elements xsinil, type
    ) Patients
for xml path('Hospital'), elements xsinil, type

Is there any way to force the container element to be present?

Answer 1

select
    (
        select
            'John Doe'
        where 1 = 0
        for xml path('Patient'), type
    )
for xml path('Patients'), root('Hospital'), type