In this case it's hard to make something fancy :)

    from sqlbind import WHERE, FIELDS, join_fragments

    q = Q()  # a QueryParams factory
    fields = []
    joins = []
    filters = []

    if some_condition:
        fields.append('sub_table.field')
        joins.append('INNER JOIN sub_table ON (subid)')
        filters.append(q.sub_table.date > since)

    sql = f'''\
    SELECT {FIELDS('table.field', *fields)}
    FROM table
    {join_fragments(' ', joins)}
    {WHERE(*filters)}
    '''

Personally I prefer this explicitness to ORM for complex queries which include recursive or multiple joins to the same table.

But I agree ORM shines with simple joins especially if models include proper relationship and there is no need to specify 'ON' condition every time.

Whenever we do recursive, or really long queries (not often), we’re dropping to basically raw SQL with sqlalchemy.text(). It’s really a lot to keep it wholly in SQLAlchemy: write a complex query in SQL, convert to SQLA, and remember how all the moving parts should be connected.

Should be much easier now with LLMs, though :)