Updating table records in SQLite with Python involves utilizing the sqlite3
module and employing the UPDATE
statement to modify existing data within a database table. The process typically involves several steps:
Import SQLite library: First, you need to import the sqlite3
module, which comes built-in with Python.
Connect to the SQLite Database: Use sqlite3.connect()
to connect to the SQLite database. If the database does not exist, this command will create it.
Create a Cursor Object: A cursor allows you to execute SQL commands in a Python script.
Execute an Update Statement: Use the cursor object to execute an UPDATE
SQL statement. This statement updates the records in the table based on your specified conditions.
Commit the Changes: After executing the UPDATE
command, you need to commit the changes to the database.
Close the Connection: Finally, close the database connection once the update is complete.
Here’s a sample Python script demonstrating these steps:
import sqlite3 # Connect to SQLite database (or create it if it doesn't exist) connection = sqlite3.connect('my_database.db') # Create a cursor object cursor = connection.cursor() # Prepare the UPDATE SQL query update_query = """ UPDATE my_table SET column_name = 'new_value' WHERE condition; """ # Execute the update query cursor.execute(update_query) # Commit the changes to the database connection.commit() # Close the connection connection.close()
In this script, my_database.db is the name of your SQLite database, my_table is the name of the table you want to update, column_name is the name of the column you want to update, ‘new_value’ is the new value you want to set, and condition is the condition that specifies which records should be updated (like id = 1).
Here is an example of updating a record in a table named employees, where you’re setting the salary to 90000 for the employee with id equal to 1:
import sqlite3 try: conn = sqlite3.connect('example.db') cursor = conn.cursor() print("Connected to SQLite") sql_update_query = """Update employees set salary = 90000 where id = 1""" cursor.execute(sql_update_query) conn.commit() print("Record Updated successfully") cursor.close() except sqlite3.Error as error: print("Failed to update sqlite table", error) finally: if conn: conn.close() print("The SQLite connection is closed")
This script updates the salary of a specific employee in the employees table.
Remember to replace these placeholders with your actual database name, table name, column names, and conditions as per your requirements.
This comprehensive guide provides a structured and professional approach to updating SQLite table records with Python. It emphasizes the importance of importing the necessary module, establishing a database connection, creating a cursor object, constructing the UPDATE statement, executing it, committing the changes, and closing the cursor and connection.