为什么这个JSON不起作用？

I want to use the MySQL remote data as the tags by using select2 plugin. But my learning curve for the JSON is very weak. Please help me in correcting this JSON format.

$("#e7").select2({
    placeholder: "Search for a movie",
    minimumInputLength: 3,
    ajax: {
        url: "search.php",
        dataType: 'jsonp',
        quietMillis: 100,
        data: function (term, page) { // page is the one-based page number tracked by Select2
            return {
                q: term, //search term
                page_limit: 10, // page size
                page: page, // page number
                apikey: "ju6z9mjyajq2djue3gbvv26t" // please do not use so this example keeps working
            };
        },
        results: function (data, page) {
            var more = (page * 10) < data.total; // whether or not there are more results available

            // notice we return the value of more so Select2 knows if more results can be loaded
            return {
                results: data.movies,
                more: more
            };
        }
    },
    formatResult: movieFormatResult, // omitted for brevity, see the source of this page
    formatSelection: movieFormatSelection, // omitted for brevity, see the source of this page
    dropdownCssClass: "bigdrop", // apply css that makes the dropdown taller
    escapeMarkup: function (m) {
        return m;
    } // we do not want to escape markup since we are displaying html in results
});

And here is the search.php

<?php
    $sql=mysqli_query($db3->connection,"SELECT * FROM tags");

    while($row=mysqli_fetch_array($sql)){
        $tags=$row['tags'];
        $id=$row['id'];

        $response=array();
        $response['tags']=$tags;
        $response['id']=$id;     
    }

    echo json_encode($response);
?>

Your while loop is not filling the $response array. $response=array(); is resetting the $response with each iteration of the loop

$sql=mysqli_query($db3->connection,"SELECT * FROM tags");

$response=array();
while($row=mysqli_fetch_array($sql)){
    $tags=$row['tags'];
    $id=$row['id'];

    $response[]=array('tags'=>$tags, 'id'=>$id);

}

echo json_encode($response);