09_delete_data.py

#!/usr/bin/python
import psycopg2
from config import config

"""
execute the DELETE statement. If you want to pass values to the DELETE statement, you use the placeholders ( %s) in the DELETE statement and pass input values to the second parameter of the execute() method.

The DELETE statement with a placeholder for the value of the id field is as follows:

DELETE FROM table_1 WHERE id = %s;

To bind value value_1 to the placeholder, you call the execute() method and pass the input value as a tuple to the second parameter like the following:

cur.execute(delete_sql, (value_1,))
"""

 
def delete_part(part_id):
    """ delete part by part id """
    conn = None
    rows_deleted = 0
    try:
        # read database configuration
        params = config()
        # connect to the PostgreSQL database
        conn = psycopg2.connect(**params)
        # create a new cursor
        cur = conn.cursor()
        # execute the UPDATE  statement
        cur.execute("DELETE FROM parts WHERE part_id = %s", (part_id,))
        # get the number of updated rows
        rows_deleted = cur.rowcount
        # Commit the changes to the database
        conn.commit()
        # Close communication with the PostgreSQL database
        cur.close()
    except (Exception, psycopg2.DatabaseError) as error:
        print(error)
    finally:
        if conn is not None:
            conn.close()
 
    return rows_deleted
    
    

if __name__ == '__main__':
    deleted_rows = delete_part(2)
    print('The number of deleted rows: ', deleted_rows)