To update documents in a TinyDB database, you can use the
update() method. This method allows you to apply changes to existing documents based on specified query conditions. Here's how you can update documents in a TinyDB database:
Define the update operations : First, you need to specify the update operations that you want to apply to the documents. These operations are represented as a dictionary, where keys are the fields to update, and values are the new values to set for those fields.
Specify the query condition : Next, you need to define a query condition that identifies the documents you want to update. You can use the Query object or a lambda function to specify the condition.
Call the update() method : Finally, call the
update() method on the table object, passing the update operations and the query condition as arguments.
Here's an example demonstrating how to update documents in a TinyDB database:
from tinydb import TinyDB, Query
# Create a new TinyDB instance with JSON file storage
db = TinyDB('db.json')
# Get a reference to the 'users' table
users_table = db.table('users')
# Define a Query object to specify the query condition
User = Query()
# Define update operations (e.g., set the 'age' field to 31 for users with 'name' equal to 'Alice')
update_operations = {'age': 31}
# Specify the query condition (e.g., find users with 'name' equal to 'Alice')
query_condition = User.name == 'Alice'
# Update matching documents in the 'users' table
users_table.update(update_operations, query_condition)?
In this example :
* We define a Query object User to specify the query condition.
* We define the update operations as a dictionary, setting the 'age' field to 31.
* We specify the query condition to find users with the 'name' equal to 'Alice'.
* We call the update() method on the 'users' table, passing the update operations and the query condition as arguments.
After executing this code, all documents in the '
users' table where the '
name' field is equal to '
Alice' will be updated to set the '
age' field to
31.
