How to put multiple rows of data from table into JSON array

Question

I would like to select the last 4 rows of my table and then put them into a JSON array with a number attached to each piece of data so I can access them later, I would think a loop but don't know how to do it with the counter being the number

The part that gets the last four rows

SELECT title FROM questions ORDER BY id DESC LIMIT 4

And the array be like 1: data one, 2: data two...

Answer 1

Aron you can use the following code:-

$mysqli = new mysqli("localhost", "dbusername", "dbpassword", "sakila");
$x = 1;
$return_arr = array();
$result = $mysqli->query("SELECT title from questions ORDER By id DESC LIMIT 4");
while( $obj = $result->fetch_object() ) {
   $row_array[$x] = $obj->title;
   $x++;
}
$result->close();
array_push($return_arr,$row_array);
echo json_encode($return_arr);`//result [{"1":"title1","2":"title2","3":"title3}]

Here in the loop, I am storing the value inside an array($row_array). Here $x will contain the number(key). Then the complete result is pushed into a new array and the result is converted into a json array.

Answer 2

1. Build a database connection string, such as using MySQLI.
2. Query the database for your rows.
3. Use the fetchAll() function to grab all rows, pass MYSQLI_NUM constant to tell it to return a numericaly indexed array as opposed to associative
4. json_encode and echo it back.

Here's what the code would look like:

$mysqli = new mysqli('localhost', 'user', 'pass', 'database');
$stmt = $mysqli->query('SELECT title FROM questions ORDER BY id DESC LIMIT 4');
echo json_encode($stmt->fetchAll(MYSQLI_NUM));

Answer 3

Check the below code using PDO, you can change to mysqli also

$dbh = new PDO('mysql:host=localhost:33060;dbname=demo', 'root', '');

$sth = $dbh->prepare("SELECT title FROM questions ORDER BY id DESC LIMIT 4");
$sth->execute();
$result = $sth->fetchAll(PDO::FETCH_COLUMN);

//Key should be string, otherwise, we can not encode as json
foreach($result as $key => $value) { 
    $newkey = sprintf('%s',$key);
    $newArray["k$newkey"] = $value; 
} 

echo json_encode($newArray); //result: {"k0":"title 4","k1":"title 3","k2":"title 2","k3":"title 1"}