SYNOPSIS

my $add_const = Monorail::Change::CreateConstrant->new(
    table       => 'train',
    name        => 'uniq_train_name_idx',
    type        => 'unique',
    field_names => [qw/name/],
);

print $add_const->as_perl;

$add_const->as_sql;

$add_const->transform_dbix($dbix)