How?

There's no way to change a variable to a constant,right?

If you template snippet would work, the data input for it would look like

$tmpl->param(loopname => [
    {
        anothervariable => 'foo',
        foo             => 'actual value',
    },
    ...
])
[download]

You need to change that to

$tmpl->param(loopname => [
    {
        
        fixed_key => 'actual value',
    },
    ...
])
[download]

For example by creating a fixed coyp of each hashref like this:

my $new = { fixed_key => $old->{$old->{anothervariable}} };
[download]

Perl 6 - second systems done right

Consider the case you use DBI to fetch the result of show tables,

whose keys are in the format Tables_in_db_name, there's no way to reduce it into a fixed key,

as it changes according to the database name .

Is there a better option than copy the whole hash into another one with fixed keys(as obviously this is causing duplicate data)?