Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation

selectcol_arrayref not working/available?

by christopherbarsuk (Acolyte)
on Aug 09, 2001 at 21:34 UTC ( #103522=categorized question: print w/replies, xml ) Need Help??
Contributed by christopherbarsuk on Aug 09, 2001 at 21:34 UTC
Q&A  > database programming


I'm using DBI with a MySQL database, and, reading through the documentation, I see the method 'selectcol_arrayref' -- when I try this method, it always returns 'undef'.

Q1: Is this method actually available?

Q2: Is there a way to determine what module is supplying an inherited method? That is, if I want to look at the code for this method, how do I determine where from it's being inherited?

Muchas thanks for any insight...

Answer: selectcol_arrayref not working/available?
contributed by tadman

I use selectcol_arrayref all the time, and it works very well. Make sure you are checking the value of your $dbh->err, and $dbh->errstr because there may be an error in your query.

The difference between selectcol_arrayref and selectall_arrayref is that the former returns a single array of all values in that column, while the latter returns an array of arrays of each row (AoA), even if each row contains only one entry. This is why the former is preferable for these kinds of circumstances.

Please (register and) log in if you wish to add an answer

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others taking refuge in the Monastery: (4)
    As of 2019-09-21 03:18 GMT
    Find Nodes?
      Voting Booth?
      The room is dark, and your next move is ...

      Results (269 votes). Check out past polls.