Question

我创建了一个api来从数据库中获取数据以将其作为json回显，最后在html中显示它，但在回显数据时，

我的PHP错误

注意：未定义的偏移量：第16行的/opt/lampp/htdocs/ReadExchange/api.php中的80

注意：未定义的偏移量：第16行/opt/lampp/htdocs/ReadExchange/api.php中的79

注意：未定义的偏移量：第16行/opt/lampp/htdocs/ReadExchange/api.php中的78

等等，

PHP代码

$db_result_set = $db->prepare('SELECT p.Id, p.FirstName, p.MiddleName, p.LastName, p.Gender, p.Location, p.Email, p.Mobile,b.BookTitle, b.BookGenre, b.BookWriter, b.BookDescription FROM personaldetails AS p LEFT JOIN bookdetails AS b ON b.UserId = p.Id ORDER BY p.Id DESC');;

$db_result_set->execute();

$final = [];
foreach ($db_result_set as $u) {

    if (!is_array($final[$u["Id"]])) {   //line 16 
        $final[$u["Id"]]= [
            "Id" => $u["Id"],
            "FirstName" => $u["FirstName"],
            "MiddleName" => $u["MiddleName"],
            "LastName" => $u["LastName"],
            "Gender" => $u["Gender"],
            "Location" => $u["Location"],
            "Email" => $u["Email"],
            "Mobile" => $u["Mobile"],
         ];
    }
    $final[$u["Id"]]["books"][] = [
        "BookTitle" => $u["BookTitle"],
        "BookGenre" => $u["BookGenre"],
        "BookWriter" => $u["BookWriter"],
        "BookDescription" => $u["BookDescription"],
    ];

}   

    header('Content-type: application/javascript');
    echo json_encode($final);

＆GT;

我不确认，但我认为因为这个我没有得到html中的json数据。

Answer 1

不是：if (!is_array($final[$u["Id"]]))

但是：if (!isset($final[$u["Id"]]))

Answer 2

您正在尝试检查数组中是否存在未定义的偏移量。您首先需要检查isset是否存在偏移量。

所以将代码更改为

if (isset($final[$u["Id"]]) && ! is_array($final[$u["Id"]))

PHP错误：注意：未定义的偏移量

2 个答案: