How to nest conjunctions or_ and and_ in SQLAlchamey

问题

I'm tyring to recreate this query in SQL Alchamey but I've been unable to nest the filters:

Query:

SELECT * FROM calendar 
where (recurrenceRule = '') 
or (recurrenceRule != '' and start < @end1);

Python:

events.filter(or_(Calendar.recurrenceRule!='',
      (Calendar.recurrenceRule=='',Calendar.start>=filterStart))

This python results in the following exception: "SQL expression object or string expected."

回答1:

You must use and_ explicitly:

events.filter(or_(
    Calendar.recurrenceRule!='',
    and_(Calendar.recurrenceRule=='', Calendar.start>=filterStart))
)

来源：https://stackoverflow.com/questions/26154009/how-to-nest-conjunctions-or-and-and-in-sqlalchamey