Best Way to Check If MySQL_Query Returned Any Results

Best way to check if mysql_query returned any results?

if (mysql_num_rows($result)==0) { PERFORM ACTION }

For PHP 5 and 7 and above use mysqli:

if (mysqli_num_rows($result)==0) { PERFORM ACTION }

How to check if mysql_query returned anything or not

You could use is_resource to make sure that it's a resource. You could alternatively use an if statement to make sure that FALSE wasn't returned.

To display the error, use mysql_error.

Example:

<?php

// From http://ca2.php.net/manual/en/function.mysql-query.php

$result = mysql_query('SELECT * WHERE 1=1');
if (!$result) {
    trigger_error('Invalid query: ' . mysql_error());
}

Checking if mysql_query returned anything or not

You could use mysql_num_rows($results) to check if 0 rows were returned, or use this faster alternative:

$query = "SELECT COUNT(*) AS total FROM table";
$results = mysql_query($query, $connection);
$values = mysql_fetch_assoc($results);
$num_rows = $values['total'];

Check whether mysql query returned an empty resultset

Finally i got the solution, may be its not the smarter way, but my purpose is solved. I changed the query as --

$stmt = $linkID1->prepare("select count(fstatus),fstatus from cae_friends where provider_email=? and request_email=?");
                            $stmt->bind_param("ss", $uid,$row['email']);
                            $stmt->execute();
                            $stmt->bind_result($val,$fstatus);
                            $stmt->fetch();


                            echo "Row Count : ".$val;

Now $val is giving out the right output.
Thanks guys

PHP Mysql how to show message when query return no result?

You shouldn't use the mysql_ functions anymore the are deprecated and don't allow you to use parameterized queries which will prevent you from being SQL injected.

Here's a way using the mysql_ functions. You can easily transistion this to mysqli or pdo because they both have the num_rows function just check the manual for their implementation.

$category = mysql_real_escape_string($_POST['category']);  
$length = mysql_real_escape_string($_POST['length']);  
$con = mysql_connect("localhost","globalex","[?H~hS=Oc=ES");
 $db = mysql_select_db("globalex",$con);
 $query = "SELECT list FROM answers WHERE category = '$category' AND length =    '$length'";
$result = mysql_query($query) or die(mysql_error());
if(mysql_num_rows($result) == 0) {
      echo "No Results";
} else { 
     while($row = mysql_fetch_array($result)) {
           echo 'Category '. $category .' '. $length .' letters: ';
           echo '<b>'. $row['0'].'</b><br>';
     }
}

You can read more about SQL injection prevention here, How can I prevent SQL injection in PHP? and more about why the mysql_ functions shouldn't be used here Why shouldn't I use mysql_* functions in PHP?.

PHP & MySQL, what's returned when the query yields no rows?

That would fall into the case of the first part of the documentation:

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

A query that returns no result rows will return neither true, nor false, but a resource object.

However, the resource object will have no rows, i.e., mysql_num_rows() will return 0 and the first call to mysql_fetch_* will return FALSE. There are a number of ways that you can detect this situation, but calling mysql_num_rows() is probably one of the easiest.

How to check if a MySQL query using the legacy API was successful?

This is the first example in the manual page for mysql_query:

$result = mysql_query('SELECT * WHERE 1=1');
if (!$result) {
    die('Invalid query: ' . mysql_error());
}

If you wish to use something other than die, then I'd suggest trigger_error.

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