在sqlalchemy中提供了Queqy.join()函数, >>> session.query(User).join(Address).filter(Address.email_address=='test@test.com').first()2015-08-1914:06:56,624INFO sqlalchemy.engine.base.EngineSELECTusers.idASusers_id, users.nameASusers_nameFROMusers INNERJOINaddressesONusers.id = addresses.user_...
session.query(User).join(Address).\ filter(Address.email_address=='jack@google.com').\ all() Query.join()知道如何加入之间User和Address因为他们之间只有一个外键 二:左连接 query.outerjoin(User.addresses)#LEFT OUTER JOIN 三:使用别名 跨多个表查询时,如果相同的表需要不止一次引用,表的SQL通常需要与...
查询 # 默认根据在类里面定义的外键进行on, 此时得到的结果是[(userobj, departmnetobj),()] 这种形式,默认是inner join r1 = session.query(User, Department).join(Department).all() r2 = session.query(, Department.title).join(Department, ==User.depart_id).all() # 有了 isouter 参数,inner joi...
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New issue Closed 问题描述 如果先执行过P69数据库关联例子的代码,再执行P72页app_with_sqlalchemy.py的时候会报错,原因是从Address表有外键连接到User,traceback如下: (venv) ❯ python app_with_sqlalchemy.py Traceback (most recent call last): File "app_with_sqlalchemy.py", line 12, in <module>...
join()方法通常从实体列表中最左边的项进行连接,如果省略了ON子句,或者ON子句是一个普通的SQL表达式。要控制连接列表中的第一个实体,可以使用Query.select_from()方法:query = session.query(User, Address).select_from(Address).join(User) 使用别名在跨多个表进行查询时,如果需要多次引用同一个表,SQL通常要求该...
要删除记录,我们使用 delete ()函数。 from sqlalchemy import delete s = delete(customers).where( customers.c.username.like('pablo%') ) print(s) rs = conn.execute(s) rs.rowcount DELETE FROM customers WHERE customers.username LIKE :username_1 2 Dealing with Duplicates 处理重复行 To deal w...
session.query(Address).with_parent(someuser, ’addresses’) >>> session.delete(jack) >>> session.query(User).filter_by(name=’jack’).count() UPDATE addresses SET user_id=? WHERE addresses.id = ? [None, 1] UPDATE addresses SET user_id=? WHERE addresses.id = ?
def process_IN_DELETE(self, session, event): print "Removing:", event.pathname delete_record = session.query(Filesystem). filter_by(path=event.pathname).one() session.delete(delete_record) def init_repository(): #Drop the table, then create again with each run ...
student_list=Student.query.filter(Student.name.like("%xiaohui%")).all()student_list=Student.query.filter(Student.name.startswith("xiao")).all()student_list=Student.query.filter(Student.name.like("___")).all() 3.3 filter_by设置精确条件查找数据 filter_by...