How do I dump blessed hash ref?

Question

  DB<126> x $dbh
0  DBI::db=HASH(0x11e0bd0)
     empty hash

It seems I can't dump its content no matter how many stuff I assign to it by $dbh->{$a} = $v

why?

Answer 1

DBI handles are an example of inside out objects; they squirrel away their attributes where you in theory can't get them except through their interface. (Unlike many newer implementations of inside out objects, they also have a tie interface that allows you to get and set attributes as if they were blessed hashes, but in a controlled way.)

Answer 2

If you are trying to debug DBI consider using DBI's powerful tracing method which works for the database driver as well as DBI itself.