Setting SQLAlchemy autoincrement start value

python sqlalchemy auto-increment

Gorthon · May 8, 2012 · Viewed 28.9k times · Source

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!

Answer

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;")
)

Setting SQLAlchemy autoincrement start value

Answer

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