Re: PHP/MySQL & Control Structures -> if (mysql_query())

On Wed, 21 Mar 2001 14:58, Mike Gifford wrote: > Hello, > > I'd like the presense or absense of information within a database to be > involved in an if statement, however I'm having trouble getting it to > work. I've set up the following: > > $same_Email_query = mysql_query("SELECT Email FROM phPetition WHERE > Email='" . $Email . "'"); > if($same_Email_query){ > $error = 1; > $error_html .= "This email \"" . $Email . "\" has already been used to > sign the petition.<br><br>\n"; > } > > In this case, I'd like the mysql_query to search the database for the > instance of the submitted $Email and if there is a duplicate entry in > the database, then I'd like the if() statement to return an error (as > lised above). > > Any idea what I'm doing wrong? $same_Email_query is a pointer to a result set from the query and will always be true if the query succeeded - where succeeded means something like 'returned 0 or more matching rows' What you need to do is check how many matching rows are returned by your query; if there are zero rows, the value doesn't exist in the database. > In a similar way I'm trying to query the database for instances of the > same IPAddress: > > $sameIP_query = mysql_query("SELECT > FirstName,LastName,CityState,IPAddress FROM phPetition WHERE > IPAddress='" . getenv('REMOTE_ADDR') . "' ORDER BY > LastName"); if > ($sameIP_query) { > > echo "The following individuals have signed this petition from the same > IP: " . getenv('REMOTE_ADDR'); > while ($sameIP_array = mysql_fetch_array($sameIP_query)) { > echo "<LI>" . stripslashes($individuals_array["FirstName"]) . > " " . > stripslashes($individuals_array["LastName"]) . " from " . > stripslashes($individuals_array["CityState"]); > } > } Shouldn't $individuals_array[ be $sameIP_array[ ? Consider using extract; if nothing else it makes code easier to read :-) > If the database already has entries which have been submitted from the > same IPAddress, I'd like to have those names and numbers listed. > > The previous version of this code is published and available here: > http://openconcept.ca/guide-petition.phtml > > Thanks. > > Mike -- David Robley | WEBMASTER & Mail List Admin RESEARCH CENTRE FOR INJURY STUDIES | http://www.nisu.flinders.edu.au/ AusEinet | http://auseinet.flinders.edu.au/ Flinders University, ADELAIDE, SOUTH AUSTRALIA