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Posted by Jerry Stuckle on 01/22/06 17:54
Joseph S. wrote:
> Hi all,
> (1) The "standard method" for handling errors when executing queries to
> a mysql database, which is shown in most tutorials and books is:
>
> mysql($query) or die("select/insert/update/delete query failed for
> table_name");
>
> Actually that is hardly what should be done in a good application.
> Every other function has a means of returning a value, often true/false
> or "0"/"1".
> I feel it is best if we had something like :
>
> $success = mysql($query);
>
> if ( $sucess) {
> //do something
> } else {
> //log error
> //show customized error page
> }
>
> True, we can do the following:
>
> mysql($query) or my_own_db_error_handler();
>
> Is there anything that I dont know or any better idea?
>
> Also, a basic question I have is - why we do have to do "or die()"? Is
> it because we need to ensure that a moment a db script gives an error,
> we have a query that has failed, so as damage control, we immediately
> terminate the script, knowing that some queries have been executed and
> others have not.
> If this is the reason to use "or die()" is it not better to use
> mysql_query("start transaction") and mysql_query("commit") or
> "rollback" and put the commit at the end of the script and the rollback
> in the above mentioned my_own_db_error_handler() ?
> Is this a good way?
>
> (2) Also, most big web hosts (shared hosting - I cannot afford to set
> up a host myself or even dedicated hosting) do not have PHP5, which
> has MySQLi which has much better MySQL functionality(bind variables
> etc) . They have PHP 4.3.x. I am under the impression that for an
> efficient PHP4 app you need to use the procedural style, since PHP4's
> OO features are "slow and inefficient". Am i correct ?
>
> Thanks in advance for your responses,
> Regards,
> JS
>
I agree. Using ... or die() is just a lazy way of damage control. I
don't use it.
A failed request should never terminate the program. Rather, it should
return some kind of failure result and allow the caller to determine
what action should be taken. And good programming practices allows the
caller to handle this "failed" result gracefully.
Unfortunately, this and other poor programming practices seem to be more
pervasive in PHP books than most other languages.
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attglobal.net
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