如何打印页面上的单个字段数据而不是整个表格内容

Question

So I have this php code that gets results from a MySQL database and cache them using Memcached. I need help taking control of how I print the results on the page.

From the code below, i need help on how I can print something like this:

        echo "<br> id: ". $row["product_id"]
. " - Name: ". $row["product_name"]. " "  
. " - Price: ". $row["retail_price"] . "<br>";

This is the code I need to be modified:

<?php

header("Content-Type:application/json");

try {

    $db_name     = 'test_db';
    $db_user     = 'test_db_user';
    $db_password = 'EXAMPLE_PASSWORD';
    $db_host     = 'localhost';

    $memcache = new Memcache();
    $memcache->addServer("127.0.0.1", 11211);

    $sql = 'SELECT
            product_id,
            product_name,
            retail_price
            FROM products
           ';

    $key = md5($sql);

    $cached_data = $memcache->get($key);

    $response = [];

    if ($cached_data != null) {

        $response['Memcache Data'] = $cached_data;

    } else {

        $pdo = new PDO("mysql:host=" . $db_host  . ";dbname=" . $db_name, $db_user, $db_password);
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

        $stmt = $pdo->prepare($sql);
        $stmt->execute();

        $products = [];

        while (($row = $stmt->fetch(PDO::FETCH_ASSOC)) !== false) {
            $products[] = $row;
        }

        $memcache->set($key, $products, false, 5);

        $response['MySQL Data'] =  $products;

    }

    echo json_encode($response, JSON_PRETTY_PRINT) . "\n";

} catch(PDOException $e) {
    $error = [];
    $error['message'] = $e->getMessage();
    echo json_encode($error, JSON_PRETTY_PRINT) . "\n";
}

Answer 1

Just like you normally would print results of SELECT query. Although here it seems there's an ajax call invovled.

header("Content-Type:application/json");

try {

    $db_name     = 'test_db';
    $db_user     = 'test_db_user';
    $db_password = 'EXAMPLE_PASSWORD';
    $db_host     = 'localhost';

    $memcache = new Memcache();
    $memcache->addServer("127.0.0.1", 11211);

    $sql = 'SELECT
            product_id,
            product_name,
            retail_price
            FROM products
           ';

    $key = md5($sql);

    $cached_data = $memcache->get($key);

    $response = [];

    $result = null;

    if ($cached_data != null) {

        $response['Memcache Data'] = $cached_data;
        $result = $cached_data;

    } else {

        $pdo = new PDO("mysql:host=" . $db_host  . ";dbname=" . $db_name, $db_user, $db_password);
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

        $stmt = $pdo->prepare($sql);
        $stmt->execute();

        $products = [];

        while (($row = $stmt->fetch(PDO::FETCH_ASSOC)) !== false) {
            $products[] = $row;
        }

        $memcache->set($key, $products, false, 5);


        $response['MySQL Data'] =  $products;
        $result = $products;

    }

    // echo json_encode($response, JSON_PRETTY_PRINT) . "\n";
    $html = "";
    foreach ($result as $row) {
      $html .= "<br> id: ". $row["product_id"]
        . " - Name: ". $row["product_name"]. " "  
        . " - Price: ". $row["retail_price"] . "<br>";
    }

    // return as HTML (won't work in ajax)
    echo $html;

    // or for ajax:
    echo json_encode($html, JSON_PRETTY_PRINT) . "\n";

    // or
    echo json_encode(["html" => $html], JSON_PRETTY_PRINT) . "\n";


} catch(PDOException $e) {
    $error = [];
    $error['message'] = $e->getMessage();
    echo json_encode($error, JSON_PRETTY_PRINT) . "\n";
}