MySQL DB迁移:更改字符串长度 [英] MySQL DB migration: change of string length

问题描述

我正在使用SQLAlchemy + Alembic来管理我的数据库.我有一个长度为10个字符的字符串字段，后来发现它必须为20个字符.因此，我更新了模型定义.

I'm using SQLAlchemy + alembic to manage my database. I had a string field which was 10 characters long and later on found out that it has to be 20. So I updated the model definition.

class Foo(db.Model):
    __tablename__ = 'foos'
    id = db.Column(db.Integer, primary_key=True)
    foo_id = db.Column(db.Integer, db.ForeignKey('users.id'))
    name = db.Column(db.String(80))

当我运行alembic revision --autogenerate时，未检测到此错误.现在，我确实阅读了文档，并怀疑这可能不受支持.如何在数据库中优雅地管理此类更改?

When I run alembic revision --autogenerate, this was not detected. Now I did read the documentation and suspected that this might not be supported. How do I managed such changes in DB gracefully?

推荐答案

您需要启用可选的列类型此以获取有关默认检查内容的注释

You need to enable optional column type checking. See this for notes on what is checked by default

context.configure(
    # ...
    compare_type = True
)

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