I am trying to use parameter substitution with SQLite within Python for an IN clause. Here is a complete running example that demonstrates: import sqlite3 c = sqlite3.connect(":memory:") c.execute('CREATE TABLE distro (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT)') for name in 'Ubuntu Fedora Puppy DSL SuSE'.split(): c.execute('INSERT INTO distro (name) VALUES (?)', [ name ] ) desired_ids = ["1", "2", "5", "47"] result_set = c.execute('SELECT * FROM distro WHERE id IN (%s)' % (", ".join(desired_ids)), ()) for result in result_set: print result It prints out: (1, u'Ubuntu') (2, u'Fedora') (5, u'SuSE') As the docs state that "[y]ou shouldn’t assemble your query using Python’s string operations because doing so is insecure; it makes your program vulnerable to an SQL injection attack," I am hoping to use parameter substitution. When I try: result_set = c.execute('SELECT * FROM distro WHERE id IN (?)', [ (", ".join(desired_ids)) ]) I get an empty result set, and when I try: result_set = c.execute('SELECT * FROM distro WHERE id IN (?)', [ desired_ids ] ) I get: InterfaceError: Error binding parameter 0 - probably unsupported type. While I hope that any answer to this simplified problem will work, I would like to point out that the actual query I want to perform is in a doubly-nested subquery. To wit: UPDATE dir_x_user SET user_revision = user_attempted_revision WHERE user_id IN (SELECT user_id FROM (SELECT user_id, MAX(revision) FROM users WHERE obfuscated_name IN ("Argl883", "Manf496", "Mook657") GROUP BY user_id ) ) Continue reading...