Unexpected error with DBD::SQLite

[Will Parsons]

This program produces an error which looks wrong to me:

-------------------------------------------------------
#!/usr/bin/env perl
use strict;
use DBI;

my $dbh = DBI->connect('dbi:SQLite:test.db', '', '',
                       { AutoCommit   => 1,
                         PrintError   => 0,
                         RaiseError   => 1 });

eval { $dbh->do("drop table X"); };

$dbh->do("create table X(a TEXT, b TEXT, unique(a, b))");

my $sth = $dbh->prepare("insert into X(a, b) values('N', ?)");

$sth->execute('1.1');
$sth->execute('1.10');
-------------------------------------------------------

When run, I see:

$ ./test-sqlite.pl 
DBD::SQLite::st execute failed: columns a, b are not unique(1) at 
dbdimp.c line 401 at ./test-sqlite.pl line 17.

Is this correct behaviour?

- Will