Is there any memory limit for json_encode() method?

Question

I am trying to echo a json-encoded array which consist of an array but i dont know it is not letting me print that thing. Here's my code:

<?php

include_once('confi.php');
header('Content-type: application/json');

if ($_SERVER['REQUEST_METHOD'] == "POST")
{
    $lastRecord = isset($_POST['lastRecordID']) ? 
                      mysql_real_escape_string($_POST['lastRecordID']) : "";

    $queryForTotalRec = mysql_query("SELECT customer_id FROM `WebServiceTesting`.`sapphire` ORDER BY customer_id DESC LIMIT 1");
    $total_rec = mysql_fetch_row($queryForTotalRec);

    if($total_rec){
        $queryForAllRecords = "SELECT * FROM `WebServiceTesting`.`sapphire` WHERE customer_ID BETWEEN %d AND %d";
       $get_all_recs = mysql_query(sprintf($queryForAllRecords, $lastRecord, $total_rec[0]));

        $json = array();
        while($row = mysql_fetch_assoc($get_all_recs)){

          $json[] = array("Status" => 1, "NewRecord" => $row);
        }

        print_r($json);
        echo json_encode($json);
   }else{
    $json = array("status" => 0, "Error_Message" => mysql_error());
          echo json_encode($json);
    }
}else{

    $json = array("status" => 0, "Error_Message" => "Request Method not correct");
      echo json_encode($json);

}
@mysql_close($conn);

Errors: Malformed JSON: Unexpected 'A' sometimes 'I'

When i am deleting the print_r line iam getting: No response received When i am printing the count of $json array iam getting a count of 153 but NO OTHER output.

Things i've tried:

i read in some solutions to similar problems that u need to use array_values() for e.g:

 echo json_encode(array_values($json));

same response: 'No response received'

I've also tried putting echo $json inside loop which I know that is conceptually wrong but still and got expected error 'Syntax error'

Also, i tried echoing through foreach no luck Syntax error but i can see output in raw but cannot validate the json.

Just for the info on print_r this is the response:

Array (
 [0] => Array ( 
     [Status] => 1 [NewRecord] => Array ( 
                   [customer_id] => 1241 
                   [firstName] => Katy 
                   [lastName] => Lest
                   [email] => [email protected] [phone] => 787012425
                                         )
               )
 [1] => Array ( 
      [Status] => 1 [NewRecord] => Array ( 
                    [customer_id] => 1242 
                    [firstName] => Hanah 
                    [lastName] => Morrisn 
                    [email] => [email protected]
                    [phone] => 144221275  )
              )
 [2] => Array (
       [Status] => 1 [NewRecord] => Array ( 
                    [customer_id] => 1243 
                    [firstName] => James 
                    [lastName] => McGrath
                    [email] => [email protected]
                    [phone] => 79684312  )
             ) 
)

Just found a sort of answer to this i am still looking for a reason if anyone can help in that please. The number of Records i was pulling were 150+ so i just tried with 50 records at a time and it worked perfectly. Anyone know how can i actually allocate more memory to my array so that it can hold all the required data at once only ?

I have also tried by giving accurate index as well i thought that array goes out of memory but this even not working:

 $json = new SplFixedArray($difference);

Your assistance would be very much appreciated.

Note: The mysql_* functions are deprecated, they have been removed from PHP 7, your code will stop working when you upgrade to that version. You should not write new code using them, use mysqli_* or PDO instead. — Gerald Schneider
– Gerald Schneider, Commented Feb 29, 2016 at 13:05
@GeraldSchneider sure i'll, actually i am working on php after a long time even at that time i was beginner so just due to familiarity with syntax i am doing this. — MQ.
– MQ., Commented Feb 29, 2016 at 13:09

Community · Accepted Answer · 2017-05-23 11:52:59Z

4

Stab into the dark: some of your database rows contain non-ASCII characters (e.g. ü, é and such). Your database connection is set to latin1, so the data is not UTF-8 encoded. json_encode requires UTF-8 encoded data. If you fetch enough rows, there will be rows with such non-UTF-8 data in there, and json_encode fails. With few enough rows you happen to not hit those problematic rows.

Test this by outputting echo json_last_error_msg(); after json_encode.

Set your database connection to UTF-8. See here how to do so: UTF-8 all the way through

The reason why your browser complains about invalid JSON when you include a print_r is simple: because then PHP outputs a lot of garbage which isn't JSON, which the browser can't decode as JSON.

edited May 23, 2017 at 11:52

CommunityBot

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answered Mar 1, 2016 at 8:26

deceze♦

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4 Comments

MQ. Over a year ago

its like very awkward situation right now, if i am echoing json encoded array with 50 entries the output is perfect but as soon as i try to exceed the limit of array it starts showing message 'no response received'. Which is currently beyond my understanding.

deceze Over a year ago

And I tried to clarify what's happening in my answer...!? Is there anything more I can clarify?

MQ. Over a year ago

O o o, i think you have pointed the exact. I have got the same error as well let me check. Great Great

MQ. Over a year ago

Thanks a ton for pointing me in the right direction @deceze !!

Manjeet Barnala · Accepted Answer · 2016-02-29 12:46:50Z

-2

Simply Use json_decode() you will get the result you need..

   $array = json_decode($json, true);
   echo "<pre>"; print_r($array);

Array
(
    [0] => Array
        (
            [Status] => 1
            [NewRecord] => Array
                (
                    [fname] => xyz
                    [lname] => abc
                    [gender] => male
                )

        )

    [1] => Array
        (
            [Status] => 1
            [NewRecord] => Array
                (
                    [fname] => 123
                    [lname] => 456
                    [gender] => male
                )

        )

    [2] => Array
        (
            [Status] => 1
            [NewRecord] => Array
                (
                    [fname] => demo
                    [lname] => vvv
                    [gender] => female
                )

        )

)

answered Feb 29, 2016 at 12:46

Manjeet Barnala

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1 Comment

MQ. Over a year ago

just found something please read the last para in my question.

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