CODEWITHSUNDEEP
pythonsqlalchemy
Blankman
Blankman

Reputation: 267010

Why doesn't sqlalchemy modify the database when I add/remove a column?

If I run my python script, it creates the tables correctly.

However, if I add/remove a column and run the script again, it doesn't modify the database.

Why is this?

I am doing this after defining everything:

mapper(Product, products)
mapper(Category, categories)

metadata.create_all(engine)

session = Session()

Upvotes: 0

Views: 1760

Answers (2)

Rick
Rick

Reputation: 16224

create_all only creates. It doesn't modify. http://www.sqlalchemy.org/docs/core/schema.html?highlight=create_all#sqlalchemy.schema.MetaData.create_all

If you've changed the columns you need to either drop/readd the table, or manually add the column outside of your script. There are tools to do this like sqlalchemy-migrate which is a full migrations manager for your project. http://code.google.com/p/sqlalchemy-migrate/

Upvotes: 4

Blender
Blender

Reputation: 298176

I use SQLAlchemy within Flask, but I think the same concepts apply here. You have to commit the changes when you change something within the database:

session.commit()

Upvotes: 0

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