Php 无法从SQLite数据库获取数据

我正在尝试运行以下查询：

SELECT nfc_film.title, nfc_film.film_id, nfc_film.description, nfc_film.release_year, nfc_film.rating, nfc_film.last_update, nfc_category.name
  FROM nfc_film
JOIN nfc_film_category
  ON nfc_film.film_id = nfc_film_category.film_id
JOIN nfc_category
  ON nfc_film_category.category_id = nfc_category.category_id  LIMIT 10 OFFSET 0

如果我将其放入“SQLite的DB浏览器”，则返回正确的字段

但当尝试在PHP中实现此功能时，它不起作用：

$filmQuery = "
SELECT nfc_film.title, nfc_film.film_id, nfc_film.description, nfc_film.release_year, nfc_film.rating, nfc_film.last_update, nfc_category.name
  FROM nfc_film
JOIN nfc_film_category
  ON nfc_film.film_id = nfc_film_category.film_id
JOIN nfc_category
  ON nfc_film_category.category_id = nfc_category.category_id ";

if($search_term && $category){
  $filmQuery .= "
  WHERE
    nfc_film.title LIKE :searchterm
  AND
    nfc_category.name = :category";
} else if ($search_term && !$category) {
  $filmQuery .= "
  WHERE
    nfc_film.title LIKE :searchterm";
} else if (!$search_term && $category) {
  $filmQuery .= "
  WHERE
    nfc_category.name = :category";
}

$filmQuery .= " LIMIT 10 OFFSET :page";

如果未找到

category

或

searchterm

，则解析为：

SELECT nfc_film.title, nfc_film.film_id, nfc_film.description, nfc_film.release_year, nfc_film.rating, nfc_film.last_update, nfc_category.name
      FROM nfc_film
    JOIN nfc_film_category
      ON nfc_film.film_id = nfc_film_category.film_id
    JOIN nfc_category
      ON nfc_film_category.category_id = nfc_category.category_id  LIMIT 10 OFFSET :page

然后，我准备、绑定并执行查询：

$sqlGetFilms = $dbConn->prepare($filmQuery);
$sqlGetFilms->bindParam(':searchterm', $sqlSearchTerm);
$sqlGetFilms->bindParam(':category', $category);
$sqlGetFilms->bindParam(':page', $page);
$sqlGetFilms->execute();
$query = $sqlGetFilms->fetchAll();

当未找到任何

searchterm

和

category

时，将返回记录。但此代码中出现的任何其他情况都不会返回任何记录，即使它们在“DB Browser for SQLite”中运行时出现

编辑： 我试过硬编码

SELECT nfc_film.title, nfc_film.film_id, nfc_film.description, nfc_film.release_year, nfc_film.rating, nfc_film.last_update, nfc_category.name
      FROM nfc_film
    JOIN nfc_film_category
      ON nfc_film.film_id = nfc_film_category.film_id
    JOIN nfc_category
      ON nfc_film_category.category_id = nfc_category.category_id 
      WHERE
        nfc_film.title LIKE '%k%' LIMIT 10 OFFSET 0

---

没有返回任何内容

您可能会发现，当您只使用一个或其他术语时，您会得到一个错误，这类似于试图绑定到一个不存在的变量。
这（我认为）取决于您有条件地构建SQL的地方，您可能有

：searchterm

或

：category

或两者都有，但您总是尝试绑定到这两个

因此，如果有一个值需要绑定，则分别绑定每个术语

if(!empty($search_term)){
    $sqlGetFilms->bindParam(':searchterm', $sqlSearchTerm);
} 
if(!empty($category)) {
    $sqlGetFilms->bindParam(':category', $category);
}