odd mysql encounter

drewbie

why do i get a non-valid result resource error with this code?if the query isn't correct it should give me the error, but it just continues with the script. and BTW, i have no clue why the query isnt working, its simple as hell, the variable $ID is available cause i can echo it out before the query

$link_id = db_connect($default_dbname);
$query = mysql_query("SELECT * FROM login WHERE ID='$ID'", $link_id) || die ("Query failed :" . mysql_error());
$num_rows = mysql_num_rows($query);
echo $num_rows;

and another wierd encounter i had a few weeks ago was that 2 variables were disappearing, $state and $zip. really odd cause i could echo them out at the top of the function, but then they wouldnt get inserted into the db cause they were all the sudden gone! so i tried setting $test = $state and $test2 = $zip at the top of the function, then used $test and $test2 in place in the insert query and they were there. anyone else have wierd problems? sometimes i get stopped by the smallest shit....errrrrrrrrrrrrrrrrrrrrrr

drewbie

WTF??!?! i took away the || die ("Query failed :" . mysql_error());
and the query worked. am i missing something here?

nemonoman

Hi drewbie:

I guess I'm a WimpyCoder.

I've seen code constructions like yours often, but I'm not inclined to use it because I worry about the chances for failure. Seeing your problem and solution makes me think I'll stay away from it.

Specifically:

$query = mysql_query("SELECT * FROM login WHERE ID='$ID'", $link_id) || die ("Query failed :" . mysql_error());

This statement, it seems to me, might yield very different results depending on the order of parsing, and depending on what the parser considers a "TRUE" condition.

It's much cooler than the WimpyCode version I would write:

$query = mysql_query("SELECT * FROM login WHERE ID='$ID'", $link_id)
if (!$query) {die ("Query failed :" . mysql_error()); }

But I don't think the WimpyCode version would fail.

I'm asking here -- this ain't rhetorical -- in your collapsed version, is there ANY GUARANTEE that the parser will run the MySQL query before testing for TRUE condition? If it runs the DIE condition -- won't the parser find that condition TRUE?

I'm asking -- is there a downside to WimpyCode, other than that I'll be called a sissy? Is there an overhead my Wimpy way that I'm not considering?

I'd like to know. Until then, I am a complete wimp, writing explcit if conditionals to test the state of a var after running the code, instead of the all in one line approach favored by Macho Programmers.

I hate surprises, and your example problem encourages me to continue to be a WimpyCoder.