in reply to Hash to Scalar?

You can use Storable

use Storable qw(nfreeze thaw); $scalar = nfreeze(\%hash); %hash_copy = %{ thaw($scalar) };

If you need to have hash with keys - usenames and values as data structure (not scalar) you can use tie... for binding to sql database use eg. Tie::RDBM module. Example from docs:

use Tie::RDBM; tie %h,Tie::RDBM,'mysql:test',{table=>'Demo',create=>1,autocommit=>0}; $h{'key1'} = 'Some data here'; $h{'key2'} = 42; $h{'key3'} = { complex=>['data','structure','here'],works=>'true' }; $h{'key4'} = new Foobar('Objects work too'); print $h{'key3'}->{complex}->[0]; tied(%h)->commit; untie %h;