设置SQLAlchemy自动增量起始值 [英] Setting SQLAlchemy autoincrement start value

问题描述

SQLAlchemy中的autoincrement参数似乎只有True和False，但是我想设置下一个插入操作时通过自动递增aid = 1002的预定义值aid = 1001./p>

在SQL中，可以像这样更改:

ALTER TABLE article AUTO_INCREMENT = 1001;

我正在使用MySQL，并且我尝试了以下操作，但不起作用:

from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class Article(Base):
    __tablename__ = 'article'
    aid = Column(INTEGER(unsigned=True, zerofill=True), 
                autoincrement=1001, primary_key=True)

那么，我该怎么办呢?预先感谢！

解决方案

您可以通过使用

The autoincrement argument in SQLAlchemy seems to be only True and False, but I want to set the pre-defined value aid = 1001, the via autoincrement aid = 1002 when the next insert is done.

In SQL, can be changed like:

ALTER TABLE article AUTO_INCREMENT = 1001;

I'm using MySQL and I have tried following, but it doesn't work:

from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class Article(Base):
    __tablename__ = 'article'
    aid = Column(INTEGER(unsigned=True, zerofill=True), 
                autoincrement=1001, primary_key=True)

So, how can I get that? Thanks in advance!

解决方案

You can achieve this by using DDLEvents. This will allow you to run additional SQL statements just after the CREATE TABLE ran. Look at the examples in the link, but I am guessing your code will look similar to below:

from sqlalchemy import event
from sqlalchemy import DDL
event.listen(
    Article.__table__,
    "after_create",
    DDL("ALTER TABLE %(table)s AUTO_INCREMENT = 1001;")
)

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