db-to-sqlite 1.5
CLI tool for exporting tables or queries from any SQL database to a SQLite file
License: Apache License, Version 2.0
Requires Python: >=3.7

# db-to-sqlite

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CLI tool for exporting tables or queries from any SQL database to a SQLite file.

## Installation

Install from PyPI like so:

    pip install db-to-sqlite

If you want to use it with MySQL, you can install the extra dependency like this:

    pip install 'db-to-sqlite[mysql]'

Installing the `mysqlclient` library on OS X can be tricky - I've found [this recipe](https://gist.github.com/simonw/90ac0afd204cd0d6d9c3135c3888d116) to work (run that before installing `db-to-sqlite`).

For PostgreSQL, use this:

    pip install 'db-to-sqlite[postgresql]'

## Usage
```
Usage: db-to-sqlite [OPTIONS] CONNECTION PATH

  Load data from any database into SQLite.

  PATH is a path to the SQLite file to create, e.c. /tmp/my_database.db

  CONNECTION is a SQLAlchemy connection string, for example:

      postgresql://localhost/my_database
      postgresql://username:passwd@localhost/my_database

      mysql://root@localhost/my_database
      mysql://username:passwd@localhost/my_database

  More: https://docs.sqlalchemy.org/en/13/core/engines.html#database-urls

Options:
  --version                     Show the version and exit.
  --all                         Detect and copy all tables
  --table TEXT                  Specific tables to copy
  --skip TEXT                   When using --all skip these tables
  --redact TEXT...              (table, column) pairs to redact with ***
  --sql TEXT                    Optional SQL query to run
  --output TEXT                 Table in which to save --sql query results
  --pk TEXT                     Optional column to use as a primary key
  --index-fks / --no-index-fks  Should foreign keys have indexes? Default on
  -p, --progress                Show progress bar
  --postgres-schema TEXT        PostgreSQL schema to use
  --help                        Show this message and exit.
```

For example, to save the content of the `blog_entry` table from a PostgreSQL database to a local file called `blog.db` you could do this:

    db-to-sqlite "postgresql://localhost/myblog" blog.db \
        --table=blog_entry

You can specify `--table` more than once.

You can also save the data from all of your tables, effectively creating a SQLite copy of your entire database. Any foreign key relationships will be detected and added to the SQLite database. For example:

    db-to-sqlite "postgresql://localhost/myblog" blog.db \
        --all

When running `--all` you can specify tables to skip using `--skip`:

    db-to-sqlite "postgresql://localhost/myblog" blog.db \
        --all \
        --skip=django_migrations

If you want to save the results of a custom SQL query, do this:

    db-to-sqlite "postgresql://localhost/myblog" output.db \
        --output=query_results \
        --sql="select id, title, created from blog_entry" \
        --pk=id

The `--output` option specifies the table that should contain the results of the query.

## Using db-to-sqlite with PostgreSQL schemas

If the tables you want to copy from your PostgreSQL database aren't in the default schema, you can specify an alternate one with the `--postgres-schema` option:

    db-to-sqlite "postgresql://localhost/myblog" blog.db \
        --all \
        --postgres-schema my_schema

## Using db-to-sqlite with MS SQL

The best way to get the connection string needed for the MS SQL connections below is to use urllib from the Standard Library as below

    params = urllib.parse.quote_plus(
        "DRIVER={SQL Server Native Client 11.0};"
        "SERVER=localhost;"
        "DATABASE=my_database;"
        "Trusted_Connection=yes;"
    )

The above will resolve to

    DRIVER%3D%7BSQL+Server+Native+Client+11.0%7D%3B+SERVER%3Dlocalhost%3B+DATABASE%3Dmy_database%3B+Trusted_Connection%3Dyes

You can then use the string above in the odbc_connect below

    mssql+pyodbc:///?odbc_connect=DRIVER%3D%7BSQL+Server+Native+Client+11.0%7D%3B+SERVER%3Dlocalhost%3B+DATABASE%3Dmy_database%3B+Trusted_Connection%3Dyes
    mssql+pyodbc:///?odbc_connect=DRIVER%3D%7BSQL+Server+Native+Client+11.0%7D%3B+SERVER%3Dlocalhost%3B+DATABASE%3Dmy_database%3B+UID%3Dusername%3B+PWD%3Dpasswd

## Using db-to-sqlite with Heroku Postgres

If you run an application on [Heroku](https://www.heroku.com/) using their [Postgres database product](https://www.heroku.com/postgres), you can use the `heroku config` command to access a compatible connection string:

    $ heroku config --app myappname | grep HEROKU_POSTG
    HEROKU_POSTGRESQL_OLIVE_URL: postgres://username:password@ec2-xxx-xxx-xxx-x.compute-1.amazonaws.com:5432/dbname

You can pass this to `db-to-sqlite` to create a local SQLite database with the data from your Heroku instance.

You can even do this using a bash one-liner:

    $ db-to-sqlite $(heroku config --app myappname | grep HEROKU_POSTG | cut -d: -f 2-) \
        /tmp/heroku.db --all -p
    1/23: django_migrations
    ...
    17/23: blog_blogmark
    [####################################]  100%
    ...

## Related projects

* [Datasette](https://github.com/simonw/datasette): A tool for exploring and publishing data. Works great with SQLite files generated using `db-to-sqlite`.
* [sqlite-utils](https://github.com/simonw/sqlite-utils): Python CLI utility and library for manipulating SQLite databases.
* [csvs-to-sqlite](https://github.com/simonw/csvs-to-sqlite): Convert CSV files into a SQLite database.

## Development

To set up this tool locally, first checkout the code. Then create a new virtual environment:

    cd db-to-sqlite
    python3 -m venv venv
    source venv/bin/activate

Or if you are using `pipenv`:

    pipenv shell

Now install the dependencies and test dependencies:

    pip install -e '.[test]'

To run the tests:

    pytest

This will skip tests against MySQL or PostgreSQL if you do not have their additional dependencies installed.

You can install those extra dependencies like so:

    pip install -e '.[test_mysql,test_postgresql]'

You can alternative use `pip install psycopg2-binary` if you cannot install the `psycopg2` dependency used by the `test_postgresql` extra.

See [Running a MySQL server using Homebrew](https://til.simonwillison.net/homebrew/mysql-homebrew) for tips on running the tests against MySQL on macOS, including how to install the `mysqlclient` dependency.

The PostgreSQL and MySQL tests default to expecting to run against servers on localhost. You can use environment variables to point them at different test database servers:

- `MYSQL_TEST_DB_CONNECTION` - defaults to `mysql://root@localhost/test_db_to_sqlite`
- `POSTGRESQL_TEST_DB_CONNECTION` - defaults to `postgresql://localhost/test_db_to_sqlite`

The database you indicate in the environment variable - `test_db_to_sqlite` by default - will be deleted and recreated on every test run.