擅长:python、mysql、java
<p>为了记录,这里是我最后使用的代码。迈克(zzzeek)的回答仍然是正确和确定的,因为这只是他的一个改编,这是我的突破。</p>
<pre><code>cits = aliased(TextString)
cyts = aliased(TextString)
cots = aliased(TextString)
for (city_id, country_text, county_text, city_text) in \
session.query(City.id, cyts.text_string, cots.text_string, cits.text_string).\
outerjoin((cits, and_(cits.id==City.text_string_id, cits.language=='en'))).\
outerjoin((County, City.county)).\
outerjoin((cots, and_(cots.id==County.text_string_id, cots.language=='en'))).\
outerjoin((Country, City.country)).\
outerjoin((cyts, and_(cyts.id==Country.text_string_id, cyts.language=='en'))):
# Python to construct the breadcrumb, checking county_text for None-ness
</code></pre>