之前自己的一个表中的关系属性是：
class Event(db.Model): __tablename__ = “events” joiners = db.relationship(‘User’, secondary=event_joiners) |
打印出来类型是：
type(firstEvent.joiners)=<class ‘sqlalchemy.orm.collections.InstrumentedList’>
现在需要：
去搞懂：
sqlalchemy.orm.collections.InstrumentedList
有哪些方法
以便于我去使用
比如去query查询之类的
sqlalchemy.orm.collections.InstrumentedList
Collection Configuration and Techniques — SQLAlchemy 1.1 Documentation
“class sqlalchemy.orm.collections.InstrumentedList
Bases: __builtin__.list
An instrumented version of the built-in list.”
python – sqlalchemy: ‘InstrumentedList’ object has no attribute ‘filter’ – Stack Overflow
What is an InstrumentedList in Python? – Stack Overflow
去改为：
joiners = db.relationship(‘User’, secondary=event_joiners, lazy=’dynamic’) |
然后看看能不用用query，结果不行：
app.logger.debug(‘firstEvent=%s, firstEvent.creator=%s, type(firstEvent.joiners)=%s, firstEvent.joiners=%s’, firstEvent, firstEvent.creator, type(firstEvent.joiners), firstEvent.joiners) |
会输出：
DEBUG in db_create [db_create.py:176]: firstEvent=<Event id=1 user_openid=oswjmv4X0cCXcfkIwjoDfCkeTVVY title=u’\u8ba8\u8bba\u65e5\u5386\u7684\u516c\u4f17\u53f7\u540d\u5b57′>, firstEvent.creator=<User nickname=u’\u793c\u8c8c’ openid=oswjmv4X0cCXcfkIwjoDfCkeTVVY avatar_static_path=img/avatar/oswjmv4X0cCXcfkIwjoDfCkeTVVY.png>, type(firstEvent.joiners)=<class ‘sqlalchemy.orm.dynamic.AppenderBaseQuery’>, firstEvent.joiners=SELECT wechat_users.openid AS wechat_users_openid, wechat_users.province AS wechat_users_province, wechat_users.avatar_url AS wechat_users_avatar_url, wechat_users.avatar_static_path AS wechat_users_avatar_static_path, wechat_users.language AS wechat_users_language, wechat_users.city AS wechat_users_city, wechat_users.country AS wechat_users_country, wechat_users.sex AS wechat_users_sex, wechat_users.nickname AS wechat_users_nickname FROM wechat_users, event_joiners WHERE :param_1 = event_joiners.event_id AND wechat_users.openid = event_joiners.joiner_openid |
What is an InstrumentedList in Python? – Stack Overflow
“Yes, SQLAlchemy uses it to implement a list-like object which is aware of insertions and deletions of related objects to an object (via one-to-many and many-to-many relationships).”
sqlalchemy.orm.collections.InstrumentedList – Nullege Python Samples
那么就去找python内部的list，有哪些函数和接口
python list
“Python列表函数&方法
Python包含以下函数:
| 序号 | 函数 |
| 1 | 比较两个列表的元素 |
| 2 | 列表元素个数 |
| 3 | 返回列表元素最大值 |
| 4 | 返回列表元素最小值 |
| 5 | 将元组转换为列表 |
Python包含以下方法:
| 序号 | 方法 |
| 1 | 在列表末尾添加新的对象 |
| 2 | 统计某个元素在列表中出现的次数 |
| 3 | 在列表末尾一次性追加另一个序列中的多个值（用新列表扩展原来的列表） |
| 4 | 从列表中找出某个值第一个匹配项的索引位置 |
| 5 | 将对象插入列表 |
| 6 | 移除列表中的一个元素（默认最后一个元素），并且返回该元素的值 |
| 7 | 移除列表中某个值的第一个匹配项 |
| 8 | 反向列表中元素 |
| 9 | 对原列表进行排序 |
“
->看来没法去query加上filter了
只能自己去循环中，获取每一个变量，然后去判断了。。。
curEvent = Event.query.filter_by(id=eventIdInt).first() app.logger.debug(“curEvent=%s”, curEvent) curEventJoiners = curEvent.joiners app.logger.debug(“curEventJoiners=%s”, curEventJoiners) hasJoined = False for eachJoiner in curEventJoiners: if eachJoiner.openid == sourceUser.openid: hasJoined = True break if hasJoined: respContent = u”您已经加入了该活动: %s” % (curEvent.title) else: curEvent.joiners.append(sourceUser) db.session.commit() respContent = u”已成功将您加入了活动: %s” % (curEvent.titile) |
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