Question

Can anyone help me solve this? I having this line code with error of

PHP Fatal error: Call to a member function fetch_assoc() on string in C:\inetpub\wwwroot\dbcontroller.php on line 26

Line 26 is this line of code: $result = $query->fetch_assoc();

<?php
class DBController {
private $host = "localhost";
private $user = "root";
private $password = " ";
private $database = "test";

function __construct() {
    $conn = $this->connectDB();
    if(!empty($conn)) {
        $this->selectDB($conn);
    }
}

function connectDB() {
    $conn = mysqli_connect($this->host,$this->user,$this->password);
    return $conn;
}

function selectDB($conn) {
    mysqli_select_db($conn,$this->database);
}


function runQuery($query) {
    $result = $query->fetch_assoc();
    // $result = mysqli_query($query);
    while($row=mysqli_fetch_assoc($result)) {
        $resultset[] = $row;
    }       
    if(!empty($resultset))
        return $resultset;
}

function numRows($query) {
    $result  = mysqli_query($query);
    $rowcount = mysqli_num_rows($result);
    return $rowcount;   
}
}
?>

Answer 1

您必须取消注释代码行 -

$result = mysqli_query($query);

并评论此行 -

$result = $query->fetch_assoc();

没有收到此错误。

Answer 2

错误非常明显。你不能在字符串中调用函数，例如

// Wrong
$name = 'Johnny';
echo $name->foo();

在你的情况下：

function runQuery($query) {
    $result = $query->fetch_assoc();
    // [...]
}

...你没有说$query包含什么，但是上下文建议是带有SQL代码的字符串。简单来说，现在是如何使用mysqli扩展。请随意查看the manual并查看一些usage examples。

Answer 3

我认为你错过了对此的争论。

$result = mysqli_query($conn, $query);

/* fetch associative array */
while ($row = $result->fetch_assoc()) {
    printf ("%s (%s)\n", $row["Name"], $row["CountryCode"]);
}

Answer 4

I changed your code, Now try.   
<?php
    class DBController {
    private $host = "localhost";
    private $user = "root";
    private $password = " ";
    private $database = "test";

    function __construct() {
        $conn = $this->connectDB();
        if(!empty($conn)) {
            $this->selectDB($conn);
        }
    }

    function connectDB() {
        $conn = mysqli_connect($this->host,$this->user,$this->password);
        return $conn;
    }

    function selectDB($conn) {
        mysqli_select_db($conn,$this->database);
    }


    function runQuery($query) {
        $result = mysqli_query($query);
        while($row= $result->fetch_assoc()) {
            $resultset[] = $row;
        }       
        if(!empty($resultset))
            return $resultset;
    }

    function numRows($query) {
        $result  = mysqli_query($query);
        $rowcount = mysqli_num_rows($result);
        return $rowcount;   
    }
    }
    ?>

PHP Fatal error: Call to a member function fetch_assoc() on string

4 个答案: