RE: [PHP] MySql Check if Value Exists in Table

That would work with this one, but in other functions, if it exists, then I get the id # like: function check_author_exists($author_email) { $SQL = "SELECT author_id, author_email FROM Author WHERE author_email like \"$author_email\""; $result = mysql_query( $SQL); $Err = mysql_error(); if (mysql_num_rows($result) > 0) { $row = mysql_fetch_array($result); return $row["author_id"]; } else return -1; } pj :-> -----Original Message----- :-> From: Dave Daniels [mailto:dave@musiccity.net] :-> Sent: Friday, August 18, 2000 2:02 PM :-> To: pjoseph@gpc.peachnet.edu; Php-General@Lists. Php. Net :-> Subject: Re: [PHP] MySql Check if Value Exists in Table :-> :-> :-> Course, this is really an SQL problem, not a PHP problem, but I would do :-> something like: :-> :-> "select count(*) from table where col_1 = $id_1 and col_2 = $id_2" :-> :-> You could handle it better by defining keys so there's no need to check :-> yourself if it exists or not. :-> :-> :-> ----- Original Message ----- :-> From: "Pam Joseph" <pjoseph@gpc.peachnet.edu> :-> To: "Php-General@Lists. Php. Net" <php-general@lists.php.net> :-> Sent: Friday, August 18, 2000 12:49 PM :-> Subject: [PHP] MySql Check if Value Exists in Table :-> :-> :-> > PHPer's, :-> > :-> > Can you help me with this code? I'm trying to see if an id :-> already exists :-> > in the table, if so give an error message. I'm getting "0 is :-> not a MYSQL :-> > result index". :-> > :-> > function check_exists($table, $col_1, $col_2, $id_1, $id_2) { :-> > :-> > $SQL = "SELECT $col_1, $col_2"; :-> > $SQL .= " FROM $table"; :-> > $SQL .= " WHERE $col_1 = $id_1 and $col_2 = $id_2"; :-> > $result = mysql_query($SQL); :-> > echo ("Result in check_exists: $result"); :-> > if (mysql_num_rows($result) > 0) { :-> > echo ("<h3>Combination of:<br> $col_1 $id_1 and :-> $col_2 :-> > $id_2 already exists in $table. Please reselect.</h3>"); :-> > exit; :-> > } :-> > else return -1; :-> > :-> > } :-> > :-> > Thanks, :-> > :-> > pj :-> > :-> > :-> > -- :-> > PHP General Mailing List (http://www.php.net/) :-> > To unsubscribe, e-mail: php-general-unsubscribe@lists.php.net :-> > For additional commands, e-mail: php-general-help@lists.php.net :-> > To contact the list administrators, e-mail: :-> php-list-admin@lists.php.net :-> > :-> :-> :-> -- :-> PHP General Mailing List (http://www.php.net/) :-> To unsubscribe, e-mail: php-general-unsubscribe@lists.php.net :-> For additional commands, e-mail: php-general-help@lists.php.net :-> To contact the list administrators, e-mail: php-list-admin@lists.php.net :-> :->