Question

我有这个PHP函数：

function userParent($Username)
{
global $con;
$Result = mysqli_query($con, "SELECT Username FROM Family WHERE Parent = '$Username' LIMIT 10");
$row = mysqli_fetch_assoc($Result);
return $row; 
}

该函数应该在数组中给我10行，但为什么我只在数组中有一个值？我试图在函数括号外测试代码，并尝试像这样添加WHILE循环：

while ($row = mysqli_fetch_assoc($Result)){
    print_r($row);
}

它有效。我以数组格式得到了10行。但它会将结果打印到屏幕上。如何使它成为变量，以便它可以在函数中返回？

感谢。

更新：根据Phil的回答，现在这是我的完整代码：

<?php
function userParent(mysqli $con, $username) {
    $stmt = $con->prepare('SELECT Username FROM Family WHERE Parent = ? LIMIT 10');
    $stmt->bind_param('s', $username);
    $stmt->execute();
    $res = $stmt->get_result();
    return $res->fetch_all(MYSQLI_ASSOC);
}

$DbServer = 'localhost';
$DbUser = 'username';
$DbPassword = 'password';
$DbName = 'dbname';
$mysqli = new mysqli($DbServer, $DbUser, $DbPassword, $DbName);

$arrayParent = userParent($mysqli, 'root');
print_r($arrayParent);

?>

但我收到此错误消息：

致命错误：在第6行的/home/myhome/public_html/test.php中调用未定义的方法mysqli_stmt :: get_result（）

Answer 1

使用return：

function userParent(mysqli &$dbms, $username){
    // You need to "escape" strings, which you would use in direct queries.
    // OR BETTER: use mysqli prepared statements with parameter binding.
    $username = mysqli_real_escape_string($dbms, $username);

    $result = mysqli_query($dbms, "SELECT Username FROM Family WHERE Parent = '$username' LIMIT 10");

    // Create temporary array for resultset:
    $buffer = array();

    // Fetch data to temporary buffer:
    while ($row = mysqli_fetch_assoc($result)){
        $buffer[] = $row;
    }

    // Free result set:
    $result->free();

    // Return buffer to global scope:
    return $buffer;
}

$users = userParent($con, 'John');

var_dump($users);

Answer 2

尝试使用mysqli_result::fetch_all

function userParent(mysqli $con, $username) {
    $stmt = $con->prepare('SELECT Username FROM Family WHERE Parent = ? LIMIT 10');
    if ($stmt === false) {
        throw new Exception($con->error, $con->errno);
    }
    $stmt->bind_param('s', $username);
    $stmt->execute();
    $res = $stmt->get_result();
    return $res->fetch_all(MYSQLI_ASSOC);
}

然后像这样称呼它

$parents = userParent($mysqli, 'some username');

如果您不了解预准备语句和参数绑定

，请阅读这些内容

更新

显然（未记录），mysqli_stmt::get_result()方法仅在使用mysqlnd驱动程序时可用。如果您无法使用此驱动程序，请尝试使用此替代方法

function userParent(mysqli $con, $username) {
    $stmt = $con->prepare('SELECT Username FROM Family WHERE Parent = ? LIMIT 10');
    if ($stmt === false) {
        throw new Exception($con->error, $con->errno);
    }

    $stmt->bind_param('s', $username);
    $stmt->execute();

    $parent = null;
    $parents = array();
    $stmt->bind_result($parent);
    while($stmt->fetch()) {
        $parents[] = $parent;
    }
    return $parents;
}

如何在PHP函数中返回while循环变量中的mysqli_fetch_assoc？

2 个答案:

更新