pass parameters to sqli and bind results to json array - php

Question

I am trying to pass parameter from $.ajax post to php page and then pass to database and get result to json.
after searching post .. I have prepared statements
$src1= $_POST['source1']; .. getting variable in src1
$stmt = $mysqli->prepare("SELECT * FROM tbl_beacons WHERE imei = ?");
$stmt->bind_param( "s", $src1);
$stmt->execute();
$stmt->bind_result($col1);
$emparray = array();
while($row =mysqli_fetch_assoc($stmt))
{
$emparray[] = $row;
}
echo json_encode($emparray);
$conn->close();
I am not getting results . i think i am not able to bind the variable to the statement correctly .
I also tried and prepare another
<?php
include("connect.php");
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$src1='270113184309336860';
$rows = array();
$emparray = array();
if ($stmt = $mysqli->prepare("SELECT * FROM tbl_beacons WHERE imei = ?")) {
$stmt -> bind_param("s", $src1);
$stmt -> execute();
$rows = fetch($stmt);
}
while($row =mysqli_fetch_assoc($rows))
{
$emparray[] = $row;
}
echo json_encode($emparray);
$conn->close();
Please suggest where I am missing ?

Answer 1

update
while($row =mysqli_fetch_assoc($stmt))
with
while($row = $stmt->fetch())

Answer 2

update
$emparray[] = $row;
to
$emparray[] = $col1;

Answer 3

You may want to populate your json_encode array using
key value pairs; where the key corresponds to the data
structure you are using in your code, and the value
corresponds to its name in the database. Notice that these
two names do not have to be the same.
echo json_encode(array(
's' => $row->s,
'im' => $row->imei,
'name' => $row->NAME));