PHP MySQL查询2个表以获取数据,并合并成一个json数组用于echo?

如何将这两个查询组合成一个php数组,以json格式回显ajax请求?每一个声明都被确认是单独工作的。
看起来像:

 'fname' => $fname,
 'lname' => $lname,
'gender' => $gender,
  'city' => $city,
 'state' => $state
   'bio' => $bio

PHP MySQL请求

<?php
include 'sqlconnection.php';
$conn = OpenCon();

$stmt = $conn->prepare('SELECT fname,lname,gender,city,state FROM users WHERE uid='.$_POST['info']);
$stmt->execute();
$stmt->bind_result($fname,$lname,$gender,$city,$state);
while($stmt->fetch()) {
    $output=array(
        'fname' => $fname,
        'lname' => $lname,
        'gender' => $gender,
        'city' => $city,
        'state' => $state
    );
}
$json=json_encode($output);
echo $json;

$stmt = $conn->prepare('SELECT bio FROM profile WHERE uid='.$_POST['info']);
$stmt->execute();
$stmt->bind_result($bio);
while($stmt->fetch()) {
    $output=array(
        'bio' => $bio
    );
}
$json=json_encode($output);
echo $json;

$stmt->close();
CloseCon($conn);
?>