Beefy Boxes and Bandwidth Generously Provided by pair Networks
more useful options

Re: Hash table

by moritz (Cardinal)
on Sep 09, 2012 at 15:04 UTC ( #992592=note: print w/replies, xml ) Need Help??

in reply to Hash table

Do hashtables in Perl always have keys?

An empty hash doesn't have any keys, but it's not the most useful case.

I am asked to create a hashtable from a database.But there is no unique values so that cant make any column as key.

I guess you haven't been asked to make a hash table just for the fun of it, but because somebody needs it. That somebody can tell you what the keys should be.

Note that even if there is no unique column in your database, there might a comination of columns that is unique, which you could then use as keys for the hash table (for example delimited by the zero-byte "\x0").

Or the user of the hash table might expect multiple values to be grouped as an array, or simply the first or last of the values.

A lil confused after hearing this requirement.

Then asked for clarification. But don't ask us, ask the one who made the requirements.

Replies are listed 'Best First'.
Re^2: Hash table
by james2vegas (Chaplain) on Sep 09, 2012 at 18:52 UTC

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://992592]
[oiskuu]: Michael Jackson died? Again?!
[LanX]: 7 awkward minutes

How do I use this? | Other CB clients
Other Users?
Others pondering the Monastery: (4)
As of 2017-08-20 18:36 GMT
Find Nodes?
    Voting Booth?
    Who is your favorite scientist and why?

    Results (317 votes). Check out past polls.