PHP - Okay, I've Been Looking At This Far Too Long... Please Help!

CREATE DEFINER=`lxc`@`::1` PROCEDURE `insertData`(IN it INT)
BEGIN
      declare i int Default 0;
      declare str char(4);
      declare p_hash int;
      myloop: loop
      set p_hash = round(rand() * 999);
      set str='book';
      insert into test.users (name,password) VALUES (concat(str,'_',i+1),PASSWORD(p_hash));
      set i = i+1;
      if (i = it) then
        leave myloop;
	end if;
    end loop myloop;
  end

Table: users
Columns:
id	int(10) UN PK AI
name	varchar(45) 
password	char(41) 

mysql> call insertData(10000);
Query OK, 1 row affected (9 min 38.22 sec)

SET TERM ^ ;
CREATE PROCEDURE INSERDATA (
    IT integer ) --iteration number
AS
DECLARE VARIABLE i integer; 
BEGIN
i = 0;
while ( i < it ) do
begin
INSERT INTO PRODUCT( CODE,NAME,PASS) VALUES(:i, 'jazz_' || :i, fb_hash(round(rand() * 999)));
i = i + 1;
end
END^
SET TERM ; ^
COMMIT;

Table: product
columns
CODE integer,
NAME varchar(45),
PASS CHAR(41)

Executing statement...
Statement executed (elapsed time: 0.063s).
31464 fetches, 11084 marks, 0 reads, 0 writes.
10000 inserts, 0 updates, 0 deletes, 5 index, 0 seq.
Delta memory: 24264 bytes.
PRODUCT: 10000 inserts. 
0 rows affected directly.
Total execution time: 0.151s
Script execution finished.

Php programmers,

I am getting this error:

Fatal error: Uncaught mysqli_sql_exception: No index used in query/prepared statement (null) in C:\xampp\htdocs\test\select_adv.php:70 Stack trace: #0 C:\xampp\htdocs\test\select_adv.php(70): mysqli_stmt_execute(Object(mysqli_stmt)) #1 {main} thrown in C:\xampp\htdocs\test\select_adv.php on line 70

Line 70 is:

	if(mysqli_stmt_execute($stmt) === FALSE)
	

Context:

	if(mysqli_stmt_prepare($stmt,$query))
        {
            mysqli_stmt_bind_param($stmt,'s',$_SESSION['search_column']);
            
            if(mysqli_stmt_execute($stmt) === FALSE)
            {
                printf("Error: %s.\n", mysqli_stmt_error($stmt));
                printf("Error: %d.\n", mysqli_stmt_errno($stmt));
            }
	

This removes the error:

	 if($stmt) === FALSE)
            {
                printf("Error: %s.\n", mysqli_stmt_error($stmt));
                printf("Error: %d.\n", mysqli_stmt_errno($stmt));
            }
	

I still want to know why this works:

	 if($stmt) === FALSE)
{
	

but this doesn't work:

	 if(mysqli_stmt_execute($stmt) === FALSE)
	{
	

Let me know.

Full Code in case you're wondering just what on earth is going on ....

	<?php
//include('error_reporting.php');
error_reporting(E_ALL);
ini_set('error_reporting',E_ALL);//Same as: error_reporting(E_ALL);
ini_set('display_errors','1');
ini_set('display_startup_errors','1');
require('conn.php');
echo __LINE__;
?>
	<form name = "search" method = "POST" action="">
<label for="keywords">Keywords:*</label>
<input type="text" name="keywords" id="keywords" placeholder="Input Keywords" required>
<br>
<label for="search_column">Search in ... ?</label>
<select name="search_column" id="search_column">
<option value="page_url">Page Url</option>
<option value="link_anchor_text">Link Anchor Text</option>
<option value="page_description">Page Description</option>
<option value="keyphrases">Keyphrase</option>
<option value="keywords">Keywords</option>
</select>
<br>
<label for="tos_agreement">Agree to TOS or not ? *</label>
<select name="tos_agreement" id="tos_agreement" required>
<option value="Yes">Yes</option>
<option value="No">No</option>
</select>
<br>
<button type="submit">Submit</button><br>
<button type="submit" value="submit">Submit</button><br>
<input type="submit" value="submit"><br>
<button name=submit value=" ">Submit</button><br>
<br>
<input type="reset">
<br>
</form>
	<?php
session_start();
echo __LINE__;
if($_SERVER['REQUEST_METHOD'] === 'POST')
{
    echo __LINE__;
    if(ISSET($_POST['submit']))
    {
        echo __LINE__;
        if(ISSET($_POST['search_column']))
        {
            $_SESSION['search_column'] = $_POST['search_column'];
            echo $_SESSION['search_column'];
            echo __LINE__;
        }
        
        //Re-write the following 4 lines ...
        mysqli_report(MYSQLI_REPORT_ALL|MYSQLI_REPORT_STRICT);
        $conn = mysqli_connect("localhost","root","","test");
        $conn->set_charset("utf8mb4");
	        //$query = "SELECT page_url,link_anchor_text,page_description,keyphrases,keywords FROM links WHERE $_SESSION['search_column'] = ?";
        $query = "SELECT page_url,link_anchor_text,page_description,keyphrases,keywords FROM links WHERE {$_SESSION['search_column']} = ?";
        //$query = "SELECT page_url,link_anchor_text,page_description,keyphrases,keywords FROM links WHERE " . $_SESSION['search_column'] . " = ?";
        
        $stmt = mysqli_stmt_init($conn);
	        if(mysqli_stmt_prepare($stmt,$query))
        {
            mysqli_stmt_bind_param($stmt,'s',$_SESSION['search_column']);
            
            if(mysqli_stmt_execute($stmt) === FALSE)
            {
                printf("Error: %s.\n", mysqli_stmt_error($stmt));
                printf("Error: %d.\n", mysqli_stmt_errno($stmt));
            }
            
            $result = mysqli_stmt_bind_result($stmt,$page_url,$link_anchor_text,$page_description,$keyphrase,$keywords);
            
            mysqli_stmt_fetch($stmt);
            
            while(mysqli_stmt_fetch($stmt))
            {
                echo "url"; echo "<br>";
                echo "anchor_text"; echo "<br>";
                echo "description"; echo "<br>";
                echo "keyphrases"; echo "<br>";
                echo "keywords"; echo "<br>";
                echo "|";
                echo "<br>";
            }
            
            mysqli_stmt_close($stmt);
            mysqli_close($conn);
        }
        else
        {
            echo "1. QUERY failed!";
        }
	        if(mysqli_stmt_prepare($stmt,$query))
        {
            mysqli_stmt_bind_param($stmt,'sssss',$_POST['page_url'],$_POST['link_anchor_text'],$_POST['page_description'],$_POST['keyphrases'],$_POST['keywords']);
            
            if(mysqli_stmt_execute($stmt) === FALSE)
            {
                printf("Error: %s.\n", mysqli_stmt_error($stmt));
                printf("Error: %d.\n", mysqli_stmt_errno($stmt));
            }
            
            $result = mysqli_stmt_get_result($stmt);
            
            while($row = mysqli_fetch_array($result,MYSQLI_ASSOC))
            {
                $page_url = $row['page_url']; echo $page_url; echo "<br>";
                $link_anchor_text = $row['link_anchor_text']; echo $link_anchor_text; echo "<br>";
                $page_description = $row['page_description']; echo $page_description; echo "<br>";
                $keyphrases = $row['keyphrases']; echo $keyphrases; echo "<br>";
                $keywords = $row['keywords']; echo $keywords; echo "<br>";
                echo "|";
                echo "<br>";
            }
            
            mysqli_stmt_close($stmt);
            mysqli_close($conn);
        }
        else
        {
            die("2. QUERY failed!");
        }
        echo '<pre>' . print_r($_POST, 1) . '</pre>';
        echo $_SESSION['search_column'];
    }
}
echo __LINE__;
	?>
	

<?php
header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past
session_set_cookie_params(0);
session_start();
?>

<html>

<head>
<meta http-equiv='cache-control' content='no-cache'>
<meta http-equiv='expires' content='0'>
<meta http-equiv='pragma' content='no-cache'>
</head>

<body>

<p>Processing...</p>


<script>
myFunction();

function myFunction() {
    setInterval(function(){

location.reload();

<?php
clearstatcache();
if(file_exists($_SESSION['filename']))
{
  $existance = true;
}
else
{  
  $existance = false;
}
?>

if("<?php echo $existance ?>")
{
  window.open("done.php","_self");
}
else
{
}

}, 5000);
}
</script>

</body>
</html>

www.myurl.com.au/hotel_details.php?hotel_id=358705&currency_code=AUD&q=%27%3A%2F%2Fwww.travelnow.com%2Ftemplates%2F451536%2Fhotels%2F358705%2Foverview%3Flang%3Den%26amp%3Bcurrency%3DAUD%26amp%3BstandardCheckin%3D12%2F17%2F2014%26amp%3BstandardCheckout%3D12%2F18%2F2014%26amp%3BroomsCount%3D1%26amp%3Brooms[0].adultsCount%3D2%27&price=149&totlday=1


How or where would I go about re-writing this I am not a professional with PHP and I have never done anything like this before