Using profilefield_base_migration.php to create a custom profile field with SQlite3 DBMS returns warning:

[phpBB Debug] PHP Warning: in file [ROOT]/phpbb/db/driver/sqlite3.php on line 218: SQLite3Result::fetchArray(): Unable to execute statement: constraint failed

This is due passing filed_id and lang_id to the DB driver in unspecified format. As they are always int we should cast them in int to prevent the error message appearance.