我正在使用 python-storm 作为 orm。多对多参考集让我头疼:(
这些是相关的对象:
class Author(object):
__storm_table__ = "author"
id = Int(primary=True)
name = Unicode()
institution_id = Int()
institution = Reference(institution_id, Institution.id)
def __init__(self, name):
self.name = name
class Paper(object):
__storm_table__ = "paper"
id = Int(primary=True)
name = Unicode()
conference_id = Int()
conference = Reference(conference_id, Conference.id)
def __init__(self, name):
self.name = name
class AuthorPapers(object):
__storm_table__ = "authorpapers"
__storm_primary__ = "author_id", "paper_id"
author_id = Int()
paper_id = Int()
相应的 sqlite 表如下所示
store.execute("CREATE TABLE if not exists author (id INTEGER PRIMARY KEY, name VARCHAR, institution_id INTEGER, FOREIGN KEY (institution_id) REFERENCES institution(id))")
store.execute("CREATE TABLE if not exists paper (id INTEGER PRIMARY KEY, name VARCHAR, conference_id INTEGER, FOREIGN KEY (conference_id) REFERENCES conference(id))")
store.execute("CREATE TABLE if not exists authorpapers (author_id INTEGER, paper_id INTEGER, PRIMARY KEY (author_id, paper_id))")
现在说如果有两个作者合作写了一篇论文
a = Author(u"Steve Rogers")
b = Author(u"Captain America")
和一张纸
p6 = Paper(u"Bunga Bunga")
所以现在我想将两位作者与论文联系起来使用
Author.papers = ReferenceSet(Author.id, AuthorPapers.author_id, Paper.id, AuthorPapers.paper_id)
并这样做
a.papers.add(p6)
b.papers.add(p6)
这是顺便说一句,它说它应该在风暴教程中工作......但我明白了
File "/usr/lib64/python2.7/site-packages/storm/references.py", line 376, in add
self._relation2.link(remote, link, True)
File "/usr/lib64/python2.7/site-packages/storm/references.py", line 624, in link
pairs = zip(self._get_local_columns(local.__class__),
File "/usr/lib64/python2.7/site-packages/storm/references.py", line 870, in _get_local_columns
for prop in self.local_key)
File "/usr/lib64/python2.7/site-packages/storm/references.py", line 870, in <genexpr>
for prop in self.local_key)
File "/usr/lib64/python2.7/site-packages/storm/properties.py", line 53, in __get__
return self._get_column(cls)
File "/usr/lib64/python2.7/site-packages/storm/properties.py", line 97, in _get_column
attr = self._detect_attr_name(cls)
File "/usr/lib64/python2.7/site-packages/storm/properties.py", line 82, in _detect_attr_name
raise RuntimeError("Property used in an unknown class")
RuntimeError: Property used in an unknown class
我现在无法真正理解这一点。