--sql and --attach options for feeding commands from SQL queries

[simonw]

Say you want to fetch Twitter profiles for a list of accounts that are stored in another database:

$ twitter-to-sqlite users-lookup users.db --attach attending.db \
    --sql "select Twitter from attending.attendes where Twitter is not null"

The SQL query you feed in is expected to return a list of screen names suitable for processing further by the command.

Should be supported by all three of:

• twitter-to-sqlite users-lookup
• twitter-to-sqlite user-timeline
• twitter-to-sqlite followers and friends

The --attach option allows other SQLite databases to be attached to the connection. Without it the SQL query will have to read from the single attached database.

[simonw]

--attach can optionally take a name for the database connection alias like this:

$ twitter-to-sqlite users-lookup users.db --attach foo:attending.db ...

If you omit the alias: bit the stem of the database (without the file extension) will be used.

[simonw]

ATTACH DATABASE "file:blah.db?mode=ro" AS foo

[simonw]

• This needs documentation.

[simonw]

I also wrote about this in https://simonwillison.net/2019/Sep/13/weeknotestwitter-sqlite-datasette-rure/