How To Model Most Recent Version As Default Version In Sqlalchemy? Mới Cập Nhật

SQLAlchemy provides several ways to update data in a database. Here are a few examples:

1. Using the update() method: This method allows you to update one or more rows in a table based on a set of criteria. Here’s an example:

sql
from sqlalchemy import update
from myapp.models import User

stmt = update(User).where(User.id == 1).values(name='John')
session.execute(stmt)
session.commit()

In this example, we are updating the name of the user with ID 1 to “John”.

1. Using object attributes: If you have a model object that represents a row in the database, you can update its attributes and then commit the changes. For example:

sql
from myapp.models import User

user = session.query(User).filter_by(id=1).first()
user.name = 'John'
session.commit()

In this example, we are updating the name attribute of the User object with ID 1 to “John”.

1. Using SQL expressions: If you need to perform a more complex update, you can use SQL expressions in combination with the update() method. For example:

sql
from sqlalchemy import update
from myapp.models import User

stmt = update(User).where(User.name == 'Bob').values(name='John', age=User.age + 1)
session.execute(stmt)
session.commit()

In this example, we are updating the name of all users named “Bob” to “John” and incrementing their age by 1.

Overall, SQLAlchemy provides a flexible and powerful way to update data in a database, allowing you to use a variety of techniques depending on your needs.