从 Redis 获取数组数据 - 如何存储和检索

Question

我一直在阅读 redis，但无法决定如何保存和检索我的数据。下面是一个从 MySQL DB 中获取数据的函数；

// Initiate redis instance
$redis = new Redis();

// Connect to elasticache instance
$redis->connect('redis-001.xxx.0001.euxw1.cache.amazonaws.com', 6379);

    function getMenu ($connection) {
    $data = array();
    $restaurant_id = $_POST['restID'];

    try {

     if($redis->exists('menu_uniqueID')) {
        // read from redis and into 2D array
        $data['data'][$row['cat_name']][] = $redis->get('menu_uniqueID');
        $data['success'] = true;
        echo json_encode($data);
        exit;
     } else {

        // Menu category & items query
        // array to store results
        $query = "SELECT
    cat.name AS cat_name,
    i.id AS item_id,
    i.name AS name,
    i.description AS description,
    i.price AS price
FROM menu_categories AS cat
INNER JOIN menu_items AS i
    ON cat.id = i.cat_id
WHERE i.rest_id = $restaurant_id";

        $result = mysqli_query($connection, $query);
        if($result) {
            while($row = mysqli_fetch_assoc($result)) {
                // read into 2D array
                $data['data'][$row['cat_name']][] = $row;
               // save into Redis
               $redis->set('menu_uniqueID', json_encode($row));
            }
        }

        $data['success'] = true;
        echo json_encode($data);
        exit;
       }
    } catch (Exception $e){
        $data = array();
        $data['success'] = false;
        $data['message'] = $e->getMessage();
        echo json_encode($data);
        exit;
    }
}

如您所见，我正在检索一个二维数组并将其传递回我的前端 (AngularJS) t 使用 ng-repeat 进行消费和显示

我希望保存此查询的结果。您还可以看到我从我的前端 ($_POST['restID']) 发送数据，这是用于搜索的参数。

所以我想做的是

第一次；

1. $query 照常进行
2. 用result_$_POST['restID']键将$query结果保存到Redis中

第二次；

1. 如果键 result_$_POST['restID'] 存在，则签入 redis
2. 如果存在，则 JSON 编码并传回前端

谢谢

Answer 1

您有一些问题，第一个$redis 必须在功能范围内。 接下来，您要保存和检索整个 json 字符串：

function getMenu ($connection) {
    // Initiate redis instance
    $redis = new Redis();

    // Connect to elasticache instance
    $redis->connect('redis-001.xxx.0001.euxw1.cache.amazonaws.com', 6379);
    $restaurant_id = $_POST['restID'];

    //check for redis cached data
    if($redis->exists('menu_' . $restaurant_id)) {
        // read json string from redit
        $json = $redis->get('menu_' . $restaurant_id);
    }else{
        //if not in redis, do query
        $data = [];


        try {

            // Menu category & items query
            // array to store results
            $query = "...WHERE i.rest_id = $restaurant_id";

            $result = mysqli_query($connection, $query);
            if($result) {
                while($row = mysqli_fetch_assoc($result)) {
                    // read into 2D array
                    $data['data'][$row['cat_name']][] = $row;
                }
            }

            $data['success'] = true;
            //create json string
            $json =  json_encode($data);
            //save in redis for latter access
            //probably you want to set expiry here as well, in case values change
            $redis->set('menu_' . $restaurant_id, $json);

        } catch (Exception $e){
            $data = [];
            $data['success'] = false;
            $data['message'] = $e->getMessage();
            $json =  json_encode($data);
        }
    }
    //echo json
    header('Content-Type: application/json');
    echo $json;
    exit;   
}