Beefy Boxes and Bandwidth Generously Provided by pair Networks Cowboy Neal with Hat
There's more than one way to do things
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
Your first example creates a table inside a transaction, and actually tries to do a rollback on failure. Many databases don't support transactional support for table creation.

Your second example however doesn't have an explicite rollback. If say, the third insert fails, the eval block leaves, but two rows have been inserted, still waiting for a commit or a rollback. If the program exits afterwards, there will be immplicite rollback, but it's more appropriate to do an explicite rollback on failure.

Also, it quickly pays off of to group the insert into a single statement, especially if the database server is on a different machine. Each ->execute() adds twice the network latency between the machine your code runs on and the database server - on top of whatever needs to be done on the database server.

I also prefer to write the boilerplate as:

local $dbh->{RaiseError} = 1; local $dbh->{PrintError} = 0; eval { $dbh->begin_work; ... queries go here ... $dbh->commit; 1; } or do { my $err = $@ || "Unknown error"; eval { $dbh->rollback; 1; } or do { $err .= "[ROLLBACK FAILED: " . ($@ || "Unknown reasons") . "]" +; } die $err; }
In particular, I rely on the return value of eval to determine whether it succeeded or failed, not $@.

In reply to Re: RFC: Databases made easy by JavaFan
in thread RFC: Databases made easy by GrandFather

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
  • Outside of code tags, you may need to use entities for some characters:
            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 taking refuge in the Monastery: (7)
    As of 2014-04-20 03:23 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      April first is:







      Results (485 votes), past polls