Thank you Michael. I learned a lot from your detailed explanation of how the update and select functions work in relation to checking for good execution.
I used if (mysql_affected_rows() == 1) and got the results I was after. I am stilling having problem with users browser caching the screen, but will post that as separate question. Again thanks for your expert help. -----Original Message----- From: Michael Stassen [mailto:[EMAIL PROTECTED] Sent: Monday, March 13, 2006 4:18 AM To: [EMAIL PROTECTED] Cc: mysql@lists.mysql.com Subject: Re: Checking for good update [EMAIL PROTECTED] wrote: > On Sun, 12 Mar 2006, Michael Stassen wrote: >> >>[EMAIL PROTECTED] wrote: >> >>>looks a bit strange to me. >>> >>>>$result = mysql_query($query) or die('Query couldn\'t >>>>executed:'.mysql_error()); >>> >>>please try something like this: >> >>Why? There's nothing wrong with the above statement. > > I've never seen logic like that before. It looks to me like > fbsd_user is trying to use the OR operator outside an if > statement. > > Is the mentioned in the php manual somewhere Michael? > >>>I've not tested this - but it looks like you are mixing sending the >>>mysql query and testing for the result of the query at the same time, >>>which AFAIK is not possible. >> >>You should try it. It works just fine, and isn't the problem. The >>problem is that you cannot treat the result of an UPDATE as if it were a >>SELECT. > > Regards > > Keith Roberts Yes, this is documented. It's also standard practice (in perl and C as well). OR is not part of an if statement, it is a logical operator. <http://www.php.net/manual/en/language.operators.logical.php> "A or B" has a value, true or false, depending on the values of A and of B. In fact, if A is true, then "A or B" is certainly true, so there's no need to look at B at all. This short-circuit evaluation, combined with the fact that every assignment returns the assigned value <http://www.php.net/manual/en/language.expressions.php>, makes a statement like this possible. $result = mysql_query($query) or die('Query error:'.mysql_error()); First, the function mysql_query() is called. Its return value is assigned to $result, *and* returned as the return value of the assignment operator (=). Now we know A. If mysql_query succeeded, its return value (A) evaluates as true, so the or operation must be true, so no need to look at B. If, on the other hand, A is false (mysql_query failed), we must evaluate B to determine the value of the "or" expression. Of course, to determine the value of B, we have to call the referenced function, die(). Michael -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
