Why doesn't the sqlite code work?

Question

SQLite

Hello, I installed sqlite3 to remove email from one file in another, only this script does not remove the contents of the second file from the first.. what could be the problem? email in files one per line are written
create table file1(line text);
create index if1 on file1(line ASC);
create table file2(line text);
create index if2 on file2(line ASC);
.import 'c:\sql\r\mail.txt' file1
.import 'c:\sql\r\r.txt' file2
.output res.txt
select * from file2 where line not in (select line from file1);

Answer 1

comm -2 -3 f1 f2 is much cooler