Hmm, at first I thought that's a great idea. But then reality hit: in this way, I would need somehow to juggle two different database versions existing at the same time while I read data from the old DB (ODB), process it and add it to the new DB (NDB). I guess I would need to rename one database and that could blow.

Whereas what my situation is: ODB exists and is running. An update is coming and a NDB must be created based on ODB's data plus some added columns for certain tables. I dump the ODB to file. I erase ODB. I create NDB with no data. I read the ODB's dumpfile, process it (to add some values for the new columns) and insert it into NDB.

So, perhaps I can exploit your idea by creating my version of mysqldump based on DBI which is friendlier to my aims.

Earlier answer: Yep, that's a good way: SHOW COLUMNS and then ask DBI to SELECT and get back all results as Perl data structure. Actually no need for SHOW COLUMNS, just a SELECT will contain a hash with column names/values. After your suggestion I saw DBI, add fields to existing table? which shows how to add columns with ALTER TABLE.

bw, bliako

In reply to Re^2: Convert an SQL insert into a Perl data structure by bliako
in thread Convert an SQL insert into a Perl data structure by bliako

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.