php encode nested json in wrong format

Question

I trying to test display a nested Json structure but the result is in wrong format.

php

while($row=$statement->fetch()){

        $value=str_replace('"','',$row['item_option_value']);
        $option[$row['item_option_name']]=explode(',',$value);
        $all[$row['oid']]=$option;

    }   
echo json_encode($all);

mysql databas structure

Here is the result when i run the script.

I want the json structure to be the right side of the screenshot. Anyone knows what's wrong?

Answer 1

You would need to empty the $option arrays then like this:

$option = []; //or $option = array(); in PHP < 5.4

This is needed in order not to keep storing the data from the previous iteration.

So:

while($row=$statement->fetch()){

    $value=str_replace('"','',$row['item_option_value']);
    $option = [];
    $option[$row['item_option_name']]=explode(',',$value);
    $all[$row['oid']]=$option;

}   
echo json_encode($all);

Answer 2

The problem is because of this line here,

$option[$row['item_option_name']]=explode(',',$value);

In each iteration of while() loop, you're appending the previously calculated $options array to $all . Instead, create an temporary array to hold intermediate result and append that to $all in each iteration, like this:

while($row=$statement->fetch()){
    $opArray = array();
    $value=str_replace('"','',$row['item_option_value']);
    $opArray[$row['item_option_name']]=explode(',',$value);
    $all[$row['oid']]=$opArray;

}   
echo json_encode($all);