def extend(cls):
#1. 多表join
#2. 多字段映射同一个model
author = User.alias()
relyed_user = User.alias()
return cls.select(cls, Question, relyed_user.id, relyed_user.nick_name, author.id, author.nick_name).join(
Question, join_type=JOIN.LEFT_OUTER, on=cls.question).switch(cls).join(author, join_type=JOIN.LEFT_OUTER, on=cls.user).switch(cls).join(
relyed_user, join_type=JOIN.LEFT_OUTER, on=cls.reply_user
)
def extend(cls):
answer_author = User.alias()
answer_relyed_user = User.alias()
return cls.select(cls, Question, answer_relyed_user.id,
answer_relyed_user.nick_name, answer_author.id,
answer_author.nick_name).join(
Question,
join_type=JOIN.LEFT_OUTER,
on=cls.question).switch(cls).join(
answer_author,
join_type=JOIN.LEFT_OUTER,
on=cls.user).switch(cls).join(
answer_relyed_user,
join_type=JOIN.LEFT_OUTER,
on=cls.reply_user)
def extend(cls):
# 多表join
# 多字段映射同一个model
author = User.alias()
relyed_user = User.alias()
return cls.select(
cls, Post, relyed_user.id, relyed_user.nick_name, author.id,
author.nick_name).join(Post,
join_type=JOIN.LEFT_OUTER,
on=cls.post).switch(cls).join(
author,
join_type=JOIN.LEFT_OUTER,
on=cls.user).switch(cls).jonin(
relyed_user,
join_type=JOIN.LEFT_OUTER,
on=cls.reply_user)
def extend(cls):
#1. 多表join
#2. 多字段映射同一个model
# alias()起别名
# switch(cls) 切换到cls 如果直接join 会报错
author = User.alias()
relyed_user = User.alias()
return cls.select(
cls, Post, relyed_user.id, relyed_user.nick_name, author.id,
author.nick_name).join(Post,
join_type=JOIN.LEFT_OUTER,
on=cls.post).switch(cls).join(
author,
join_type=JOIN.LEFT_OUTER,
on=cls.user).switch(cls).join(
relyed_user,
join_type=JOIN.LEFT_OUTER,
on=cls.reply_user)
