Beefy Boxes and Bandwidth Generously Provided by pair Networks
Keep It Simple, Stupid
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

After a few months of trading it turns out that discounts would be a good thing for customers spending over a certain amount. To accomodate this the database (and code) needs to be changed.

Actually, I would think that for adding such functionality you would only need to add to a DB, not actually modify the existing structure. (I dont consider table additions to be a modification.) Perhaps your tables weren't sufficiently normalized? ;-) (Code changes would for sure be required.)

Anyway, snarkyness aside, my approach with stuff like this tends to be to write a perl script that does the DB modification via SQL. I test it on copies of the production DB, and then once happy and the code is approved for production run it on the production DB. I like to use the perl script to run the SQL because I find that its usually the easiest way to ensure newly added fields have the appropriate values assigned to them. For instance, ill use alter table to add a field as nullable, walk the table updating each record so it has the correct value, then alter table again to set it not-nullable, and perhaps add an index on the new columns.

Anyway, good luck.


---
demerphq

    First they ignore you, then they laugh at you, then they fight you, then you win.
    -- Gandhi



In reply to Re: Re: Re: OT: Ways of managing changes to a database's structure during a project. by demerphq
in thread OT: Ways of managing changes to a database's structure during a project. by EvdB

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!
  • 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?
    Username:
    Password:

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

    How do I use this? | Other CB clients
    Other Users?
    Others chanting in the Monastery: (9)
    As of 2015-07-03 11:42 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









      Results (51 votes), past polls