fastlite
provides some little quality-of-life improvements for
interactive use of the wonderful
sqlite-utils library. It’s likely
to be particularly of interest to folks using Jupyter.
pip install fastlite
from sqlite_utils import Database
from fastlite import *
from fastcore.utils import *
We demonstrate fastlite
‘s features here using the ’chinook’ sample
database.
url = 'https://github.com/lerocha/chinook-database/raw/master/ChinookDatabase/DataSources/Chinook_Sqlite.sqlite'
path = Path('chinook.sqlite')
if not path.exists(): urlsave(url, path)
db = Database("chinook.sqlite")
Databases have a t
property that lists all tables:
dt = db.t
dt
Album, Artist, Customer, Employee, Genre, Invoice, InvoiceLine, MediaType, Playlist, PlaylistTrack, Track
You can use this to grab a single table…:
artist = dt.Artist
artist
<Table Artist (ArtistId, Name)>
…or multiple tables at once:
dt['Artist','Album','Track','Genre','MediaType']
[<Table Artist (ArtistId, Name)>,
<Table Album (AlbumId, Title, ArtistId)>,
<Table Track (TrackId, Name, AlbumId, MediaTypeId, GenreId, Composer, Milliseconds, Bytes, UnitPrice)>,
<Table Genre (GenreId, Name)>,
<Table MediaType (MediaTypeId, Name)>]
It also provides auto-complete in Jupyter, IPython, and nearly any other interactive Python environment:
Column work in a similar way to tables, using the c
property:
ac = artist.c
ac
ArtistId, Name
Auto-complete works for columns too:
Columns, tables, and view stringify in a format suitable for including in SQL statements. That means you can use auto-complete in f-strings.
qry = f"select * from {artist} where {ac.Name} like 'AC/%'"
print(qry)
select * from "Artist" where "Artist"."Name" like 'AC/%'
You can view the results of a select query using q
:
db.q(qry)
[{'ArtistId': 1, 'Name': 'AC/DC'}]
Views can be accessed through the v
property:
album = dt.Album
acca_sql = f"""select {album}.*
from {album} join {artist} using (ArtistId)
where {ac.Name} like 'AC/%'"""
db.create_view("AccaDaccaAlbums", acca_sql, replace=True)
db.q(f"select * from {db.v.AccaDaccaAlbums}")
[{'AlbumId': 1,
'Title': 'For Those About To Rock We Salute You',
'ArtistId': 1},
{'AlbumId': 4, 'Title': 'Let There Be Rock', 'ArtistId': 1}]
If you have graphviz installed, you can create database diagrams:
diagram(db.tables)
Pass a subset of columns to just diagram those. You can also adjust the size and aspect ratio.
diagram(db.t['Artist','Album','Track','Genre','MediaType'], size=8, ratio=0.4)