How can I list the tables in a SQLite database file that was opened with ATTACH?

• When you use the ATTACH command in SQLite to add another database file to your current session, you might want to list all the tables from that attached database. This is useful to understand its structure and what data you can work with.
  
• Here’s how you can do it:
  
• Use the sqlite_master table:
  

 Every SQLite database has a special table called sqlite_master that stores metadata about tables, indexes, and other schema objects. To list tables in the attached database, query its sqlite_master table.

Basic query format:

 Suppose you attached a database file with the alias attached_db. You can list its tables by running:

  SELECT name FROM attached_db.sqlite_master WHERE type='table';

 This will return the names of all tables in the attached database.

Including system tables:

 Usually, you’ll want to exclude internal SQLite tables like sqlite_sequence. So, you can add a condition to filter only user tables if needed.

Listing tables from multiple attached databases:

 If you have multiple databases attached, replace attached_db with the alias of the relevant database.

Why is this useful?

 When working with multiple databases, this helps you dynamically explore the schema without opening each file separately.

Summary:

• After attaching a database with ATTACH 'filename' AS attached_db;,
  
• Run SELECT name FROM attached_db.sqlite_master WHERE type='table';
  
• This lists all user tables inside that attached database.
  
• This approach is straightforward and works well for quick schema inspections when handling multiple SQLite files in one session.