example.php

function getChapterContent(PDO $db)
{
    $sql = "SELECT id FROM Document WHERE slug = '2015-International--Building-Code' LIMIT 1";
    $stmt = $db->query($sql);
    $books = $stmt->fetchAll(PDO::FETCH_ASSOC);
    if (empty($books)) {
        echo "\nFailure!";
        return false;
    }
    $bookId = $books[0]['id'];
    $chapterContentSql = <<<'SQL'
SELECT c.* FROM Content c
JOIN Document d on d.id = c.documentID AND d.slug = '2015-International--Building-Code'
JOIN Types t on t.id = c.typeID AND t.typeName = 'chapter'
JOIN TextContent tc on tc.contentID = c.id
WHERE tc.text LIKE '%id="IBC2015_Ch07"%'
LIMIT 1
SQL;
    $stmt = $db->query($chapterContentSql);
    $chapters = $stmt->fetchAll(PDO::FETCH_ASSOC);
    if (empty($chapters)) {
        echo "\nFailure!";
        return false;
    } else {
        echo "\nFound the chapter... now building... this takes a while...";
    }
    return processContents($chapters, $bookId, $db);
}
/**
 * @param array $contents
 */
function processContents(array $contents, $documentId, PDO $db, $level = 0)
{
    $output = '';
    foreach ($contents as $contentRow) {
        // Find the type...
        $stmt = $db->query('SELECT * FROM TextContent WHERE contentID = '.$contentRow['id']);
        $text = $stmt->fetchAll(PDO::FETCH_ASSOC);
        if (!empty($text)) {
            if (count($text) > 1) {
                throw new \Exception('MULTIPLES!');
            }
            $output .= processTextContent($contentRow, $text[0], $db);
        } else {
            $stmt = $db->query('SELECT * FROM FileContent WHERE contentID = '.$contentRow['id']);
            $file = $stmt->fetchAll(PDO::FETCH_ASSOC);
            if (!empty($file)) {
                $output .= processFileContent($contentRow, $file[0], $db);
            } else {
                $stmt = $db->query('SELECT * FROM TableContent WHERE contentID = '.$contentRow['id']);
                $table = $stmt->fetchAll(PDO::FETCH_ASSOC);
                if (!empty($table)) {
                    $output .= processTableContent($contentRow, $table[0], $db);
                } else {
                    throw new \Exception('NO CONTENT FOUND.');
                }
            }
        }
        $stmt = $db->query(sprintf('SELECT * FROM Content WHERE documentID = %d AND parentContentID = %d', $documentId, $contentRow['id']));
        $childContents = $stmt->fetchAll(PDO::FETCH_ASSOC);
        if (!empty($childContents)) {
            $output .= processContents($childContents, $documentId, $db, $level + 1);
        }
    }
    return $output;
}