Beefy Boxes and Bandwidth Generously Provided by pair Networks
There's more than one way to do things

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
This is not a Perl related question directly. But indirectly it might evolve into a very useful Perl module for users of DBI. Or maybe what I want exists already and have I just not been able to find it.

What I'm looking for is a Perl module that will take two SQL CREATE TABLE definitions (in the same dialect of SQL) and finds out whether they're different in functionality. If and only if they are different, then a method taking a database handle should make the necessary changes to the table in question in a transparent manner.

An example (in MySQL). Before:

CREATE TABLE foo ( id int unsigned primary key, name varchar(255) )


CREATE TABLE foo ( id int unsigned primary key, name varchar(255), status tinyint unsigned )

Would execute:

ALTER TABLE foo ADD status tinyint unsigned

It seems that Alzabo is doing something like this under the covers. But I want to have this as a stand-alone module.

Class::AutoDB seems to offer some ideas in this direction as well, but claims the automatic update to be overkill for their application of the module.

Other modules that seem to go in this direction are DBIx-DBSchema, SQL::Schema and DB::Introspector. They all seem to be about abstracting table definitions, but not about updating actual table schema in the database itself.

Some of my questions:

  • Am I re-inventing the wheel here?
  • Have I missed other generally available modules that do something related to this?
  • Should I just extract what I need from Alzabo?

Any feedback will be very much appreciated.


In reply to Automatically altering tables from different schema's by liz

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, 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 all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others surveying the Monastery: (5)
    As of 2018-06-21 04:53 GMT
    Find Nodes?
      Voting Booth?
      Should cpanminus be part of the standard Perl release?

      Results (117 votes). Check out past polls.