定向塔，SQlite和自动增量字段 [英] Pylons, SQlite and autoincrementing fields

问题描述

嘿！ 刚开始与SQLAlchemy一起使用Pylons，我的模型如下所示:

Hey! Just started working with Pylons in conjunction with SQLAlchemy, and my model looks something like this:

from sqlalchemy import Column
from sqlalchemy.types import Integer, String

from helloworld.model.meta import Base

class Person(Base):
    __tablename__ = "person"

    id = Column(Integer, primary_key=True)
    name = Column(String(100))
    email = Column(String(100))

    def __init__(self, name='', email=''):
        self.name = name
        self.email = email

    def __repr__(self):
        return "<Person('%s')" % self.name

为避免sqlite重用可能已删除的ID，我想将AUTOINCREMENT添加到"id"列中.我仔细阅读了sqlalchemy的文档，发现可以发出sqlite_autoincrement. 可以找到这里.

To avoid sqlite reusing id's that might have been deleted, I want to add AUTOINCREMENT to the column "id". I've looked through the documentation for sqlalchemy and saw that the sqlite_autoincrement can be issued. An example where this attribute is given can be found here.

sqlite_autoincrement似乎是在创建表本身时发出的，我只是想知道当使用声明性样式的模型(例如mine)时如何提供它.

sqlite_autoincrement seems though to be issued when creating the table itself, and I just wondered how it can be supplied when using a declarative style of the model such as mine.

推荐答案

尝试将__table_args__属性与您将以传统(非声明性)数据定义样式传递给Table构造函数的参数一起使用，例如:

Try including a __table_args__ attribute with the arguments you would pass to Table constructors in the traditional (non-declarative) data definition style, e.g.:

class Person(Base):
    __tablename__ = "person"
    __table_args__ = {'sqlite_autoincrement': True}

如果必须包含多个参数，请改用这种形式(字典必须在最后):

If you have to include several arguments, use this form instead (dict has to be last):

__table_args__ = (
    Unique('foo'),
    # ...
    {'sqlite_autoincrement': True}
)

从表配置部分声明性的SQLAlchemy文档:

From the Table configuration section of the Declarative SQLAlchemy documentation:

使用__table_args__类属性指定除名称，元数据和映射的Column自变量以外的

表自变量.此属性可容纳通常发送到Table构造函数的位置参数和关键字参数.

Table arguments other than the name, metadata, and mapped Column arguments are specified using the __table_args__ class attribute. This attribute accommodates both positional as well as keyword arguments that are normally sent to the Table constructor.

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