Python Data Persistence – Deleting Rows
Similarly, we can programmatically delete a certain record from a table. This operation is also more often than not conditional. Hence, the ‘WHERE’ clause appears in the parameterized DELETE query. Following script (deleteqry.py) deletes row belonging to the user-specified product.
import sqlite3 conn=sqlite3.connect('mydb.sqlite') nm=input('enter product to delete:1) qry='delete from Products where name=?' cur=conn.cursor( ) try: cur.execute(qry, (nm,)) print ('record deleted') conn.commit ( ) except: print ('error in delete operation') conn.rollback( ) conn.close( )
- Python Data Persistence – RDBMS Concepts
- Python Data Persistence – Inserting Rows
- Python Data Persistence – Core – Updating Records
To delete the user input product, run the above script from the command prompt.
E:\python37>python deleteqry.py enter product to delete: Printer record deleted
Execute select query in SQLite console to verify that deleted product doesn’t appear in the list.
sqlite> select * from products; ProductID Name Price --------- --------- -------- 1 Laptop 25000 2 TV 32000 3 Router 2000 4 Scanner 5000 6 Mobile 15000
The next section explains how to programmatically retrieve records from a table.