Question

如果这根本没有任何意义，我很抱歉。我创建了一个名为“filmdetails.php”的PHP文件，它将列出给定电影的所有细节：

    <?php

    require_once 'dbcon_sakila.php';

    $film_id = $_GET['filmid'];

    $sql = 'SELECT title, description, release_year, rental_duration, rental_rate, length, replacement_cost, rating, special_features, film.last_update, category.name, actor.first_name, actor.last_name
    FROM film, film_category, category, film_actor, actor
    WHERE film.film_id = film_category.film_id
    AND category.category_id = film_category.category_id
    AND film.film_id = film_actor.film_id
    AND film_actor.actor_id = actor.actor_id
    AND film.film_id = ?';
    $stmt = $link->prepare($sql);
    $stmt->bind_param('i', $film_id);
    $stmt->bind_result($title, $description, $release_year, $rental_duration, $rental_rate, $length, $replacement_cost, $rating, $special_features, $last_update, $category_name, $first_name, $last_name);

    $stmt->execute();

    while ($stmt->fetch()) {
    echo '<p>Title: ' . $title . '</p>';
    echo '<p>Description: ' . $description . '</p>';
    echo '<p>Release year: ' . $release_year . '</p>';
    echo '<p>Rental duration: ' . $rental_duration . '</p>';
    echo '<p>Rental rate: ' . $rental_rate . '</p>';
    echo '<p>Length: ' . $length . '</p>';
    echo '<p>Replacement cost: ' . $replacement_cost . '</p>';
    echo '<p>Rating: ' . $rating . '</p>';
    echo '<p>Special features: ' . $special_features . '</p>';
    echo '<p>Last updated: ' . $last_update . '</p>';
    echo '<p>Categories: ' . $category_name . '</p>';
    echo '<p>First name: ' . $first_name . '</p>';
    echo '<p>Last name: ' . $last_name . '</p>';
    }

    ?>

问题在于，当我选择一部特定的电影（在我的浏览器中）时，它会重复自己，但电影中的不同演员。例如：

Title: ALLEY EVOLUTION
Description: A Fast-Paced Drama of a Robot And a Composer who must Battle a Astronaut in New Orleans
Release year: 2006
Rental duration: 6
Rental rate: 2.99
Length: 180
Replacement cost: 23.99
Rating: NC-17
Special features: Trailers,Commentaries
Last updated: 2006-02-15 05:03:42
Categories: Foreign
First name: KARL
Last name: BERRY

Title: ALLEY EVOLUTION
Description: A Fast-Paced Drama of a Robot And a Composer who must Battle a Astronaut in New Orleans
Release year: 2006
Rental duration: 6
Rental rate: 2.99
Length: 180
Replacement cost: 23.99
Rating: NC-17
Special features: Trailers,Commentaries
Last updated: 2006-02-15 05:03:42
Categories: Foreign
First name: JUDE
Last name: CRUISE

依旧......

如何防止这种情况？我真的需要制作更多的SELECT语句吗？

Answer 1

因为您在电影和演员之间存在一对多关系，所以您将获得多个结果。每个Actor的一条记录。这是RDBMS的本质。

解决方案是从您的查询中取出actor表格，并在While循环中仅使用actor查询film_id表格（您可以需要在初始查询中返回）。然后，您可以在actor查询的结果中单独循环，并将它们添加到您的页面中。

我在PHP上生锈了，但它看起来像是：

<?php

    require_once 'dbcon_sakila.php';

    $film_id = $_GET['filmid'];

    $sql = 'SELECT film_id, title, description, release_year, rental_duration, rental_rate, length, replacement_cost, rating, special_features, film.last_update, category.name 
        FROM film, film_category, category
        WHERE film.film_id = film_category.film_id
            AND category.category_id = film_category.category_id            
            AND film.film_id = ?';

    $stmt = $link->prepare($sql);
    $stmt->bind_param('i', $film_id);
    $stmt->bind_result($title, $description, $release_year, $rental_duration, $rental_rate, $length, $replacement_cost, $rating, $special_features, $last_update, $category_name);

    $stmt->execute();

    while ($stmt->fetch()) {
        echo '<p>Title: ' . $title . '</p>';
        echo '<p>Description: ' . $description . '</p>';
        echo '<p>Release year: ' . $release_year . '</p>';
        echo '<p>Rental duration: ' . $rental_duration . '</p>';
        echo '<p>Rental rate: ' . $rental_rate . '</p>';
        echo '<p>Length: ' . $length . '</p>';
        echo '<p>Replacement cost: ' . $replacement_cost . '</p>';
        echo '<p>Rating: ' . $rating . '</p>';
        echo '<p>Special features: ' . $special_features . '</p>';
        echo '<p>Last updated: ' . $last_update . '</p>';
        echo '<p>Categories: ' . $category_name . '</p>';


        $actorsql = 'SELECT actor_id, first_name, last_name
            FROM film_actor, film
            WHERE film_actor.actor_id = actor.actor_id                 
                AND film_actor.film_id = '.$film_id.';';

        $actorstmt = $link->prepare($actorsql);
        $actorstmt->bind_param('i', $actor_id);
        $actorstmt->bind_result($actor_id, $first_name, $last_name);

        while ($actorstmt->fetch()) {
            echo '<p>Actor: ' . $first_name . ' ' . $last_name . '</p>';
        }
    }

?>

再次......生锈的PHP，但这是基本的想法。这将打印电影细节，然后贯穿电影中的演员并在电影信息下逐一打印。

Answer 2

在SQL语句末尾使用GROUP BY film_actor.actor_id

PHP - 来自SQL db的数据重复自身

2 个答案: