473 posts tagged “sqlite”
SQLite is the world's most widely deployed database engine.
2020
Refactoring databases with sqlite-utils extract
Yesterday I described the new sqlite-utils transform mechanism for applying SQLite table transformations that go beyond those supported by ALTER TABLE. The other new feature in sqlite-utils 2.20 builds on that capability to allow you to refactor a database table by extracting columns into separate tables. I’ve called it sqlite-utils extract.
Executing advanced ALTER TABLE operations in SQLite
SQLite’s ALTER TABLE has some significant limitations: it can’t drop columns (UPDATE: that was fixed in SQLite 3.35.0 in March 2021), it can’t alter NOT NULL status, it can’t change column types. Since I spend a lot of time with SQLite these days I’ve written some code to fix this—both from Python and as a command-line utility.
[... 689 words]DuckDB (via) This is a really interesting, relatively new database. It’s kind of a weird hybrid between SQLite and PostgreSQL: it uses the PostgreSQL parser but models itself after SQLite in that databases are a single file and the code is designed for use as an embedded library, distributed in a single amalgamation C++ file (SQLite uses a C amalgamation). It features a “columnar-vectorized query execution engine” inspired by MonetDB (also by the DuckDB authors) and is hence designed to run analytical queries really quickly. You can install it using “pip install duckdb”—the resulting module feels similar to Python’s sqlite3, and follows roughly the same DBAPI pattern.
Weeknotes: datasette-dump, sqlite-backup, talks
I spent some time this week digging into Python’s sqlite3 internals. I also gave two talks and recorded a third, due to air at PyGotham in October.
[... 928 words]Weeknotes: Installing Datasette with Homebrew, more GraphQL, WAL in SQLite
This week I’ve been working on making Datasette easier to install, plus wide-ranging improvements to the Datasette GraphQL plugin.
[... 1,009 words]GraphQL in Datasette with the new datasette-graphql plugin
This week I’ve mostly been building datasette-graphql, a plugin that adds GraphQL query support to Datasette.
[... 1,249 words]sqlite-utils 2.14 (via) I finally figured out porter stemming with SQLite full-text search today—it turns out it’s as easy as adding tokenize=’porter’ to the CREATE VIRTUAL TABLE statement. So I just shipped sqlite-utils 2.14 with a tokenize= option (plus the ability to insert binary file data from stdin).
Fun with binary data and SQLite
This week I’ve been mainly experimenting with binary data storage in SQLite. sqlite-utils can now insert data from binary files, and datasette-media can serve content over HTTP that originated as binary BLOBs in a database file.
[... 957 words]sqlite-utils 2.12 (via) I’ve been experimenting with ways of improving BLOB support in Datasette and sqlite-utils. This new version of sqlite-utils includes a “sqlite-utils insert-files” command, which can recursively crawl directories for files and add their contents to SQLite with configurable columns containing their metadata.
I was inspired by Paul Ford who has been creating multi-GB SQLite databases of images and PDFs. It turns out that when disk space is cheap this is a pretty effective way of working with interesting corpuses of documents and images.
Weeknotes: cookiecutter templates, better plugin documentation, sqlite-generate
I spent this week spreading myself between a bunch of smaller projects, and finally getting familiar with cookiecutter. I wrote about my datasette-plugin cookiecutter template earlier in the week; here’s what else I’ve been working on.
[... 703 words]sqlite-generate (via) I wrote this tool today to generate arbitrarily large SQLite databases, for testing purposes. You tell it how many tables, columns and rows you want and it will use the Faker Python library to generate random data and populate the tables with it.
Using SQL to Look Through All of Your iMessage Text Messages (via) Dan Kelch shows how to access the iMessage SQLite database at ~/Library/Messages/chat.db—it’s protected under macOS Catalina so you have to enable Full Disk Access in the privacy settings first. I usually use the macOS terminal app but I installed iTerm for this because I’d rather enable full disk access to a separate terminal program than let anything I’m running in my regular terminal take advantage of it. It worked! Now I can run “datasette ~/Library/Messages/chat.db” to browse my messages.
Using SQL to find my best photo of a pelican according to Apple Photos
According to the Apple Photos internal SQLite database, this is the most aesthetically pleasing photograph I have ever taken of a pelican:
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