Manual parameter substitution in sqlite3

[Skip Montanaro]

Most of the time (well, all the time if you're smart), you let the
database adapter do parameter substitution for you to avoid SQL
injection attacks (or stupid users). So:

    curs.execute("select * from mumble where key = ?", (key,))

If you want to select from several possible keys, it would be nice to
be able to do this:

    curs.execute("select * from mumble where key in (?)", (keys,))

but that doesn't work. Instead, you need to do your own parameter
substitution. The quick-and-insecure way to do this is:

    curs.execute("select * from mumble where key in (%s)" %
                        ",".join([repr(k) for k in keys]))

I'm pretty sure that's breakable.

Some database adapters provide a function to do explicit substitution
(e.g., mySQLdb.escape, psycopg2._param_escape), but the sqlite3
adapter doesn't. Is there a function floating around out there which
does the right thing, allowing you to safely construct these sorts of
set inclusion clauses?

Thx,

Skip