Couldn't get column count in database

Question

I'm trying to pull number of rows seen in mysql database, but all I see is an error code. I have tried everything I know, I also checked PHP documentation but to no avail.

Code below

function signIn($email, $phone, $appName) {
        $conn = mysql_connect("localhost", "root", "");

        if ($conn) {
            $db = mysql_select_db("ahyoxsoft_registration");
        }
        if ($db) {
            $result_set = mysql_query("SELECT id FROM user_registration_info WHERE 
                email_address =". $email." AND phone_no =".$phone. " LIMIT 1");
                //echo ("No of rows :".mysql_num_rows($result_set));
            if ( (mysql_num_rows($result_set)) == 1 ) {
                $found = mysql_fetch_array($result_set);
                $_SESSION['user_id'] = $found['id'];
                header("Location: downloads/".$appName);    
            }//end if
        }
        mysql_close($conn);  
    }//end function signIn

Error

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in C:\wamp\www\ahyoxsoft\includes\login.php on line 25

extra tip. your should use exit(); or __halt_compiler(); after header("Location: downloads/".$appName); this way the browser gets the header redirect and php stops with executing — Raymond Nijland, Sep 03 '14 at 15:18

score 1 · Answer 1 · answered Sep 03 '14 at 15:07

when the result of mysql_query returns a boolean, this means you SQL query was incorrect; you forgot quotes:

$result_set = mysql_query("SELECT id FROM user_registration_info WHERE 
            email_address ='". $email."' AND phone_no ='".$phone. "' LIMIT 1");

But: while this may work, it is also susceptible for other errors and SQL injection. Read up on prepared statements and the PDO and MySQLi drivers. In fact, the mysql_* functions are deprecated.

score 0 · Answer 2 · answered Sep 03 '14 at 15:11

0

For SELECT, SHOW, DESCRIBE, EXPLAIN and other statements returning resultset, mysql_query() returns a resource on success, or FALSE on error.

Your sql query is executed with an error, so mysql_query returned false. check mysql_error ()

answered Sep 03 '14 at 15:11

netdog

91
3

oh yeah, email and phone not enclosed in quotes, – netdog Sep 03 '14 at 15:15

score -2 · Answer 3 · answered Sep 03 '14 at 15:05

-2

You've got your code to run so that it will only fetch the array information if there is exactly 1 row. Change your code to the following:

            if ( (mysql_num_rows($result_set)) >= 1 ) {
                $found = mysql_fetch_array($result_set);
                $_SESSION['user_id'] = $found['id'];
                header("Location: downloads/".$appName);    
            }//end if

answered Sep 03 '14 at 15:05

aashnisshah

464
4
10

Not quite, if a query returns no rows, `mysql_num_rows` just returns `0`, instead of `false`. – Bart Friederichs Sep 03 '14 at 15:08
@aashnisshah I tried editing it but to no avail. Still trows the same error – user3655892 Sep 03 '14 at 15:08

Couldn't get column count in database

3 Answers3