php - PDO比较两个具有不同格式的阵列

我有两个数组：
已通过表单填充的$ teachArray。
$ learnArray是PDO Select查询的结果。

我想使用array_diff（）函数将$ teachArray与$ learnArray进行比较，以便将新数据插入到我的数据库中。

我不知道如何正确地将$ learnArray转换为与$ teachArray相同的格式。

当我print_r（$ teachArray）时，我得到的结果是：Array（[0] => 1 [1] => 2）
当我print_r（$ learnArray）时，得到以下结果：Array（[0] => Array（[language_id] => 1）[1] => Array（[language_id] => 2））

if(isset($_POST['teach']))
        {
            $teachArray = $_POST['teach'];

            $sqlGet = "SELECT language_id FROM language_skill WHERE person_id = :person_id AND language_learning = :language_learning";
            $query = $handler->prepare($sqlGet);
            $query->bindValue(':person_id', $_SESSION['person_id']);
            $query->bindValue(':language_learning', 1);
            $query->execute();
            $number_of_rows = $query->rowCount();
            $learnArray = $query->fetchAll(PDO::FETCH_ASSOC); **// How do I correctly fetch it.**

            $sqlInsertTeach = "INSERT INTO language_skill (person_id, language_id, language_learning, language_teaching)
                               VALUES(:person_id, :language_id, :language_learning, :language_teaching)";

            if ($number_of_rows > 0) {
                $differentLanguageChosen = array_diff($teachArray, $learnArray);
                foreach ($differentLanguageChosen as $dataTeach) {
                    $query = $handler->prepare($sqlInsertTeach);
                    $query->bindValue(':person_id', $_SESSION['person_id']);
                    $query->bindValue(':language_id', $dataTeach);
                    $query->bindValue(':language_learning', 0);
                    $query->bindValue(':language_teaching', 1);
                    $query->execute();
                }
            }
        }

最佳答案

更换

$learnArray = $query->fetchAll(PDO::FETCH_ASSOC);

与

$learnArray = [];
while ($row = $query->fetch(PDO::FETCH_ASSOC)) {
    $learnArray[] = $row['language_id'];
}

甚至更简单：

$learnArray = $query->fetchAll(PDO::FETCH_COLUMN, 0);

其中，0是要获取的列的索引。因为只有language_id列-索引为0。

关于php - PDO比较两个具有不同格式的阵列，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/43704485/