from day12 import orm_m2m from sqlalchemy.orm import sessionmaker Session_class = sessionmaker(bind=orm_m2m.engine) Session =Session_class()#游标 '''插入数据''' Python = orm_m2m.Book(name="Python", pub_date="2018-07-17") Java = orm_m2m.Book(name="JAVA", pub_date="2018-07-16") Php = orm_m2m.Book(name="PHP", pub_date="2018-07-15") a1 = orm_m2m.Author(name="xiaopang") a2 = orm_m2m.Author(name="dapangpang") a3 = orm_m2m.Author(name="Xiaopang_to_Dapangpang") # Python.authors=[a1,a2] # Java.authors=[a1,a2,a3] # Php.authors = [a1,a3] # Session.add_all([Python,Java,Php,a1,a2]) '''查询数据''' #查找dapangpang这个作者创作了几本书 author_obj =Session.query(orm_m2m.Author).filter(orm_m2m.Author.name=="dapangpang").first() print(author_obj) #查找orm_m2m.Book.id==1的这本书有几个作者 book_obj =Session.query(orm_m2m.Book).filter(orm_m2m.Book.id==2).first() print(book_obj.authors) '''删除数据''' book_obj =Session.query(orm_m2m.Book).filter(orm_m2m.Book.id==1).first() book_obj.authors.remove(author_obj)#从一本书里删除一个作者 #删除作者 author_obj =Session.query(orm_m2m.Author).filter(orm_m2m.Author.name=="dapangpang").first() Session.delete(author_obj) Session.commit()#提交
Mysql-Sqlalchemy-ORM-many_to_many
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转载自www.cnblogs.com/fuyuteng/p/9328396.html
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