8. RDBMS and SQL

Activity 8.01: Retrieving Data Accurately from Databases

Solution:

These are the steps to complete this activity:

1. Connect to the supplied petsdb database:

   import sqlite3
   conn = sqlite3.connect("petsdb")

2. Write a function to check whether the connection has been successful:

   # a tiny function to make sure the connection is successful
   def is_opened(conn):
       try:
           conn.execute("SELECT * FROM persons LIMIT 1")
           return True
       except sqlite3.ProgrammingError as e:
           print("Connection closed {}".format(e))
           return False
   print(is_opened(conn))

   The output is as follows:

   True

3. Close the connection:

   conn.close()

4. Check whether the connection is open or closed:

   print(is_opened(conn))

   The output is as follows...