Using PHP multidimensional arrays to convert MySQL to JSON

Question

Here\'s my table structure.

I\'m trying to convert MySQL to nested JSON, but am having trouble figuring out how to build the multidimensional array in PHP.

T

Answer 1

Change your while to this:

while ($row = mysqli_fetch_assoc($fetch)) {
    $row_array[$row['school_name']]['school_name'] = $row['school_name'];
    $row_array[$row['school_name']]['terms']['term_name'] = $row['term_name'];
    $row_array[$row['school_name']]['terms']['department_name'][] = array(
        'department_name' => $row['department_name'],
        'department_code' => $row['department_code']
    );
}

Edit

If you want to achieve result like the example, maybe you should consider using this method:

<?php

$result_array = array();

$fetch_school = mysqli_query($con, "SELECT id, school_name FROM schools") or die(mysqli_error($con));
while ($row_school = mysqli_fetch_assoc($fetch_school)) {
    $result_array['school_name'] = $row_school['school_name'];

    $fetch_term = mysqli_query($con, "SELECT term_name FROM term_names WHERE school_id = $row_school['id']") or die(mysqli_error($con));
    while ($row_term = mysqli_fetch_assoc($fetch_term)) {
        $result_array['terms']['term_name'] = $row_term['term_name'];

        $fetch_dept = mysqli_query($con, "SELECT id, department_name, department_code FROM departments WHERE school_id = $row_school['id']") or die(mysqli_error($con));
        while ($row_dept = mysqli_fetch_assoc($fetch_dept)) {
            $result_array['terms']['deptartments']['department_name'] = $row_dept['department_name'];
            $result_array['terms']['deptartments']['department_code'] = $row_dept['department_code'];

            $fetch_course = mysqli_query($con, "SELECT course_name, course_code FROM adoptions WHERE departement_id = $row_dept['id']") or die(mysqli_error($con));
            while ($row_course = mysqli_fetch_assoc($fetch_course)) {
                $result_array['terms']['deptartments']['courses']['course_name'] = $row_course['course_name'];
                $result_array['terms']['deptartments']['courses']['course_code'] = $row_course['course_code'];
            }
        }
    }
}

file_put_contents("data/iMadeJSON.json" , json_encode($result_array, JSON_PRETTY_PRINT));

Probably it's not an effective program, but it should gives you best result. Hope it helps :)

Answer 2

I know that this is a kind of an old question, but today I was with the same issue. I didn't find a proper solution online and finally I solved, so I'm posting here so others can check.

I'm not 100% sure that this will work because I don't have your DB, but in my case was similar and worked. Also it will not be 100% like it was asked, but I'm pretty sure there will be no redundancy and all the data will be shown.

while ($row = mysqli_fetch_assoc($fetch)) {
$row_array ['school_name'][$row['school_name']]['terms'][$row['term_name']]['departments']['department_code'][$row['department_code']]['department_name'] = $row['department_name'];
$row_array ['school_name'][$row['school_name']]['terms'][$row['term_name']]['departments']['department_code'][$row['department_code']]['courses']['course_code'][$row['course_code']]['course_name'] = $row['course_name'];
$row_array ['school_name'][$row['school_name']]['terms'][$row['term_name']]['departments']['department_code'][$row['department_code']]['courses']['course_code'][$row['course_code']]['sections']['unique_id'][$row['magento_course_id']]['section_code'] = $row['section_code'];
}

Also I'm not a PHP guy, but from what I understand, the = comes before a leaf and only before a leaf.

Answer 3

I started from Ian Mustafa reply and I figure out to solve the problem of each loop erasing the previous array.

It's an old thread but I think this could be useful to others so here is my solution, but based on my own data structure (easy to figure out how to adapt it to other structures I think) :

$usersList_array =array();
$user_array = array();
$note_array = array();

$fetch_users = mysqli_query($mysqli, "SELECT ID, Surname, Name FROM tb_Users WHERE Name LIKE 'G%' ORDER BY ID") or die(mysqli_error($mysqli));
while ($row_users = mysqli_fetch_assoc($fetch_users)) {
    $user_array['id'] = $row_users['ID'];
    $user_array['surnameName'] = $row_users['Surname'].' '.$row_users['Name'];
    $user_array['notes'] = array();

    $fetch_notes = mysqli_query($mysqli, "SELECT id, dateIns, type, content FROM tb_Notes WHERE fk_RefTable = 'tb_Users' AND fk_RefID = ".$row_users['ID']."") or die(mysqli_error($mysqli));
    while ($row_notes = mysqli_fetch_assoc($fetch_notes)) {
        $note_array['id']=$row_notes['id'];
        $note_array['dateIns']=$row_notes['dateIns'];
        $note_array['type']=$row_notes['type'];
        $note_array['content']=$row_notes['content'];
        array_push($user_array['notes'],$note_array);
    }

    array_push($usersList_array,$user_array);
}

$jsonData = json_encode($usersList_array, JSON_PRETTY_PRINT);


echo $jsonData; 

Resulting JSON :

[
{
    "id": "1",
    "surnameName": "Xyz Giorgio",
    "notes": [
        {
            "id": "1",
            "dateIns": "2016-05-01 03:10:45",
            "type": "warning",
            "content": "warning test"
        },
        {
            "id": "2",
            "dateIns": "2016-05-18 20:51:32",
            "type": "error",
            "content": "error test"
        },
        {
            "id": "3",
            "dateIns": "2016-05-18 20:53:00",
            "type": "info",
            "content": "info test"
        }
    ]
},
{
    "id": "2",
    "cognomeNome": "Xyz Georg",
    "notes": [
        {
            "id": "4",
            "dateIns": "2016-05-20 14:38:20",
            "type": "warning",
            "content": "georg warning"
        },
        {
            "id": "5",
            "dateIns": "2016-05-20 14:38:20",
            "type": "info",
            "content": "georg info"
        }
    ]
}
]

Answer 4

Try replacing your while loop with below code:

$departments = array();
$courses = array();

$i = 0;
$j = 0;

while ($row = mysqli_fetch_assoc($fetch)) {
    $row_array[$row['school_name']]['school_name'] = $row['school_name'];
    $row_array[$row['school_name']]['terms']['term_name'] = $row['term_name'];

    $key = array_search($row['department_code'], $departments); 
    if ($key === FALSE) {        
        $k = $i++;
        $departments[] = $row['department_code'];
        $row_array[$row['school_name']]['terms']['departments'][$k]['department_name'] = $row['department_name'];
        $row_array[$row['school_name']]['terms']['departments'][$k]['department_code'] = $row['department_code'];
    } else {
        $k = $key;
    }   

    $skey = array_search($row['course_code'], $courses); 
    if ($skey === FALSE) {        
        $l = $j++;
        $courses[] = $row['course_code'];
        $row_array[$row['school_name']]['terms']['departments'][$k]['courses'][$l]['course_name'] = $row['course_name'];
        $row_array[$row['school_name']]['terms']['departments'][$k]['courses'][$l]['course_code'] = $row['course_code'];
    } else {
        $l = $skey;
    } 

    $row_array[$row['school_name']]['terms']['departments'][$k]['courses'][$l]['sections'][] = array('section_code' => $row['section_code'], 'unique_id' => $row['magento_course_id']);
}

Hope this would help you.