Question

我正在将Python Sqlalchemy用于MYSQL数据库。我编写了以下脚本来创建类对象，然后在表中添加了一些行。

from sqlalchemy import create_engine, MetaData, Table, Column, ForeignKey
from sqlalchemy.dialects.mysql.base import VARCHAR, LONGTEXT, INTEGER
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base

engine = create_engine("mysql+mysqldb://root:@localhost/mydb")
connection = engine.connect()

Session = sessionmaker(bind=engine)
session = Session()
Base = declarative_base()
metadata = MetaData()

class User(Base):
    __tablename__ = 'User'
    id = Column('id', INTEGER(display_width=11), primary_key=True, nullable=False)
    email = Column('email', VARCHAR(charset='utf8mb4', collation='utf8mb4_0900_ai_ci', length=100), unique=True)
    password = Column('password', VARCHAR(charset='utf8mb4', collation='utf8mb4_0900_ai_ci', length=45))
    name = Column('name', VARCHAR(charset='utf8mb4', collation='utf8mb4_0900_ai_ci', length=100))

现在，我需要从“用户”表中获取所有行，所以我要这样做：

user = session.query(User).all()
print(user)

但是我得到的输出不是表数据，而是这个：

[<__main__.User object at 0x7f10b0c6ebe0>, <__main__.User object at 0x7f10b0c6ec50>]

如何从表格中获取实际数据？任何帮助将不胜感激

Answer 1

您将获得的输出是记录的元组。因此，使用循环

   users = session.query(User).all()
   for user in users:
        print (user)
        print (user.id, user.email, user.password, user.name)

Answer 2

您应该在User类中编写__str__方法，例如：

class User(Base):
    ...

    def __str__(self):
        str_out = 'id={} email={} password={} name={}'
        str_formated = str_out.format(self.id,self.email,self.password,self.name)
        return str_formated

如何查询表的所有行

2 个答案: