MySQLi prepared statement - Commands out of sync still returning results

Question

I've either lost the plot or someone is playing with my mind :/

I have separated this code from the rest of my application to try and debug, also hardcoded $guideid for ease of reading.

I have the following code (There is nothing else in this script as a test ie no other queries) :

     <?php
     define("DB_HOST", "127.0.0.1");
     define("DB_NAME", "xxxxx");
     define("DB_USER", "xxxxx");
     define("DB_PASS", "xxxxx");

     $mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);

     $stmt = $mysqli->prepare("SELECT `guides_listings`.`listing_id`, `guide_slug`, `guide_name_en`, listing_name, `listing_slug`, `slogo`.`filename` AS `slogoname`, `hlogo`.`filename` AS `hlogoname`, `vlogo`.`filename` AS `vlogoname`

                                      FROM `guides_listings`
                                      JOIN `guides` ON `guides_listings`.`listing_guide` = `guides`.`guide_id`
                                      LEFT JOIN `guides_listings_pics` AS `slogo`
                                        ON `slogo`.`listing_id` = `guides_listings`.`listing_id`
                                        AND `slogo`.`type` = 'slogo'
                                      LEFT JOIN `guides_listings_pics` AS `hlogo`
                                        ON `hlogo`.`listing_id` = `guides_listings`.`listing_id`
                                        AND `hlogo`.`type` = 'hlogo'
                                      LEFT JOIN `guides_listings_pics` AS `vlogo`
                                        ON `vlogo`.`listing_id` = `guides_listings`.`listing_id`
                                        AND `vlogo`.`type` = 'vlogo'
                                      WHERE (`slogo`.`filename` IS NOT NULL OR `hlogo`.`filename` IS NOT NULL OR `vlogo`.`filename` IS NOT NULL)
                                        AND `guides_listings`.`listing_guide` = ?
                                      GROUP BY `guides_listings`.`listing_id`
                                      ORDER BY RAND() 
                                      LIMIT 12");

    $stmt->bind_param("i",$guideid);
    $guideid = 2;   

    $stmt->execute();       

    $stmt->bind_result($listing_id,$guide_slug,$guide_name,$listing_name,$listing_slug,$slogo,$hlogo,$vlogo);           

    while($stmt->fetch()) {
        $results->data[] = array('listing_id'=>$listing_id,'guide_slug'=>$guide_slug,'guide_name'=>$guide_name,'listing_name'=>$listing_name,'listing_slug'=>$listing_slug,'slogo'=>$slogo,'hlogo'=>$hlogo,'vlogo'=>$vlogo);
    }

    $stmt->close();
    ?>

This results in Commands out of sync; you can't run this command now Commands out of sync; you can't run this command now after execute()

However the correct results are still returned.

Am I missing something obvious as to why it still works yet issues this error?

EDIT

I've just carried out some testing and this seems to be happening on all prepared queries, see example below:

$mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);

$stmt = $mysqli->stmt_init();
$stmt->prepare("SELECT `listing_id` FROM `guides_listings` LIMIT 1");
$stmt->execute(); 

print_r($mysqli);  

$stmt->bind_result($listing_id);           

$stmt->fetch();
$results->data[] = array('listing_id'=>$listing_id);
$stmt->close();

The print_r results in this:

mysqli Object
(
[affected_rows] => -1
[client_info] => 5.6.21
[client_version] => 50621
[connect_errno] => 0
[connect_error] => 
[errno] => 0
[error] => 
[error_list] => Array
    (
    )

[field_count] => 1
[host_info] => 127.0.0.1 via TCP/IP
[info] => 
[insert_id] => 0
[server_info] => 5.6.21
[server_version] => 50621
[stat] => Commands out of sync; you can't run this command now
[sqlstate] => HY000
[protocol_version] => 10
[thread_id] => 19462371
[warning_count] => 0
)

Maybe I'm actually looking at a bug here?

Answer 1

• Assign $guideid before the bind.

• Try calling $stmt->store_result() between execute() and bind_result() .

• It doesn't look like $stmt is actually defined. Typically I do $stmt = mysqli->prepare(...)

Answer 2

Without Prepared Statement:

$mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);
if ($stmt= $mysqli->query("SELECT `listing_id` FROM `guides_listings` LIMIT 1")) {
    $stmt->bind_result($listing_id);           
    $stmt->fetch();
    echo "listing_id = ". $listing_id;
    $stmt->close();
}else{
    printf("Error: %s\n", $mysqli->error);
}
$mysqli->close();

With Prepared statement:

$mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);

if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
$query = "SELECT `listing_id` FROM `guides_listings` LIMIT 1";
if ($stmt = $mysqli->prepare($query)) {
    $stmt->execute();
     /* store result */
    $stmt->store_result();
    if($stmt->num_rows > 0){
    $stmt->bind_result($listing_id);
        if ($stmt->fetch()) {
            echo "listing_id = ". $listing_id;
        }
    }
    /* free result */
    $stmt->free_result();
    $stmt->close();
}else{
    /*failed to prepare*/
    printf("Error: %s\n", $mysqli->error);
}
$mysqli->close();

With Prepared Statement (Full Code):

<?php
define("DB_HOST", "127.0.0.1");
define("DB_NAME", "xxxxx");
define("DB_USER", "xxxxx");
define("DB_PASS", "xxxxx");

$mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);

if ($mysqli->connect_errno) {
    printf("Connect failed: %s\n", $mysqli->connect_error);
    exit();
}

$query = "
SELECT `guides_listings`.`listing_id`, 
       `guide_slug`, 
       `guide_name_en`, 
       listing_name, 
       `listing_slug`, 
       `slogo`.`filename` AS `slogoname`, 
       `hlogo`.`filename` AS `hlogoname`, 
       `vlogo`.`filename` AS `vlogoname` 
FROM   `guides_listings` 
       JOIN `guides` 
         ON `guides_listings`.`listing_guide` = `guides`.`guide_id` 
       LEFT JOIN `guides_listings_pics` AS `slogo` 
              ON `slogo`.`listing_id` = `guides_listings`.`listing_id` 
                 AND `slogo`.`type` = 'slogo' 
       LEFT JOIN `guides_listings_pics` AS `hlogo` 
              ON `hlogo`.`listing_id` = `guides_listings`.`listing_id` 
                 AND `hlogo`.`type` = 'hlogo' 
       LEFT JOIN `guides_listings_pics` AS `vlogo` 
              ON `vlogo`.`listing_id` = `guides_listings`.`listing_id` 
                 AND `vlogo`.`type` = 'vlogo' 
WHERE  ( `slogo`.`filename` IS NOT NULL 
          OR `hlogo`.`filename` IS NOT NULL 
          OR `vlogo`.`filename` IS NOT NULL ) 
       AND `guides_listings`.`listing_guide` = ? 
GROUP  BY `guides_listings`.`listing_id` 
ORDER  BY Rand() 
LIMIT  12 
";

$guideid = 2;  


if ($stmt = $mysqli->prepare($query)) { 
    $stmt->bind_param("i", $guideid);
    $stmt->execute();   
    $stmt->store_result();
    $stmt->bind_result($listing_id,$guide_slug,$guide_name,$listing_name,
                       $listing_slug,$slogo,$hlogo,$vlogo);           
    $results= array();     
    while($stmt->fetch()) {
        $results[] = array(
           'listing_id'=>$listing_id,'guide_slug'=>$guide_slug,
           'guide_name'=>$guide_name,'listing_name'=>$listing_name,
           'listing_slug'=>$listing_slug,'slogo'=>$slogo,
           'hlogo'=>$hlogo,'vlogo'=>$vlogo
        );
    }
    $stmt->free_result();
    $stmt->close();

}else{
    $results[] = array("Error:" => $stmt->error);
}

/* close connection */
$mysqli->close();
/* Output results in JSON*/
echo json_encode($results);