Um, period_diff is a MySQL extension. So is year_month. (Most useful ways of dealing with dates in databases tend to be extensions.)

After messing around with http://www.postgresql.org/docs/8.2/static/functions-datetime.html the best that I could find in PostgreSQL looks something like this: 

SELECT
    12 * extract(year from date1) + extract(month from date1)
      - 12 * extract(year from date2) - extract (month from date2)
        as month_spread
FROM foo

[download]
(I guess my Perl solution was longer, but it was more obvious code for me.)

In reply to Re^4: Excel automatically pulling data from Perl? by tilly
in thread Excel automatically pulling data from Perl? by tilly

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • 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, details, 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, summary, 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.