sqldiff

The sqldiff program comes with the installation of SQLite. It can help creating migration scripts by showing the differences between two databases.

We have a before and after schema:

CREATE TABLE person (
    id INTEGER PRIMARY KEY,
    name TEXT
);

CREATE TABLE person (
    id INTEGER PRIMARY KEY,
    name TEXT UNIQUE NOT NULL,
    phone TEXT NOT NULL
);

We create two db files and run the sqldiff command on these files.

rm -f /tmp/before.db /tmp/after.db
~/bin/sqlite3 /tmp/before.db < examples/before.sql
~/bin/sqlite3 /tmp/after.db < examples/after.sql
~/bin/sqldiff /tmp/before.db /tmp/after.db

This is the output we get:

ALTER TABLE person ADD COLUMN phone;