PHP PDO MYSQL 连接

Question

我有一个名为 cms_page 的表，其中每个页面都有一个 ID。我想从该表中提取所有信息，并从 cms_page_part 表中提取所有信息，其中 page_id 等于我发送到页面的 ID...我知道这很令人困惑，但这是我的尝试:

require '../../config.php';
$conn = new PDO(DB_DSN, DB_USER, DB_PASS);

$id = (int)$_GET['id'];
//$q = $conn->query("SELECT * FROM cms_page WHERE id=$id"); 
$q = $conn->query("SELECT cms_page.id, cms_page.title, cms_page.slug, cms_page_part.* FROM cms_page LEFT JOIN cms_page_part ON cms_page_part.page_id=cms_page.id WHERE cms_page.id = $id"); 

$project = $q->fetch(PDO::FETCH_ASSOC);

任何关于如何加入这些的帮助将不胜感激。

Answer 1

如何连接两个表:

SELECT id, title, slug, cms_page_part.* FROM cms_page JOIN cms_page_part ON cms_page.id = cms_page_part.page_id WHERE cms_page.id=$id

我在评论中所说的示例:

// Connect to database
$conn = new PDO(DB_DSN, DB_USER, DB_PASS);

// Page ID
$id = (int) $_GET['id'];

// Fetch page
$pageStmt = $conn->query(sprintf('SELECT * FROM cms_page WHERE id=%d', $id));
if ($pageStmt->fetchColumn() != 0) {
    $page = $pageStmt->fetch(PDO::FETCH_ASSOC);

    // Fetch parts
    $partsStmt = $conn->query(sprintf('SELECT * FROM cms_page_parts WHERE page_id=%d', $id));
    while ($part = $partsStmt->fetch(PDO::FETCH_ASSOC)) {
        // ...
    }
    $partsStmt->closeCursor();
}
$pageStmt->closeCursor();

示例(带有准备好的语句):

// Connect to database
$conn = new PDO(DB_DSN, DB_USER, DB_PASS);

// Page ID
$id = (int) $_GET['id'];

// Fetch page
$pageStmt = $conn->query('SELECT * FROM cms_page WHERE id=:id');
if ($pageStmt->execute(array(':id' => $id))) {
    if ($pageStmt->fetchColumn() != 0) {
        $page = $pageStmt->fetch(PDO::FETCH_ASSOC);

        // Fetch parts
        $partsStmt = $conn->query('SELECT * FROM cms_page_parts WHERE page_id=:id');
        if ($partsStmt->execute(array(':id' => $id))) {
            while ($part = $partsStmt->fetch(PDO::FETCH_ASSOC)) {
                // ...
            }
            $partsStmt->closeCursor();
        }
    }
    $pageStmt->closeCursor();
}