7.2. SQLite3 Connect

  • File database - persistent storage

  • In-memory - very fast, but volatile

  • sqlite3.connect() -> connection

  • connection.close()

7.2.1. In-Memory Database

  • Useful for tests, development and demonstrations

  • Very fast (do not write any data to disk)

  • Remember to close connection

Connection to in-memory database:

>>> import sqlite3
>>>
>>>
>>> db = sqlite3.connect(':memory:')
>>> db.close()

7.2.2. File Database

  • Connection will create file if not exists

  • Remember to close connection

Connection to database file:

>>> import sqlite3
>>>
>>>
>>> db = sqlite3.connect('/tmp/myfile.db')
>>> db.close()

7.2.3. Context Managers

  • Prefer using context manager

  • No need to remember about closing connection

  • Prepare your data and statements before connection

  • Works with either in-memory or file database

>>> import sqlite3
>>>
>>>
>>> DATABASE = ':memory:'
>>>
>>> with sqlite3.connect(DATABASE) as db:
...     pass

7.2.4. Debug

  • conn.set_trace_callback(print)

  • Registers trace_callback to be called for each SQL statement that is actually executed by the SQLite backend.

  • The only argument passed to the callback is the statement (as string) that is being executed.

>>> import sqlite3
>>>
>>>
>>> DATABASE = ':memory:'
>>>
>>> with sqlite3.connect(DATABASE) as db:
...     db.set_trace_callback(print)