Question

我正在尝试学习如何在我的PHP中使用预准备语句，以从MySQL数据库中获取数据。目前我没有打印任何东西。

我需要有一个while循环来遍历我在数据库中的行。这是对的吗？

我在这里是正确的方式，还是我错过了什么？我在代码中做了一些评论来描述我在做什么。

    <?php

    $stmt = $mysqli->prepare("SELECT * FROM fantasies WHERE headline = ? AND description = ? AND place = ? ORDER BY reg_date DESC LIMIT 3");

                // Execute prepared statement 
                if ($stmt->execute()) {
                    $success = true;
                }

                // Make variables ready
                $head = null;
                $desc = null;
                $plac = null;

                // Bind result to variables
                $stmt->bind_result($head, $desc, $plac);

                while ($stmt->fetch()) {

                    // What should go here?
                    echo "Headline: ".$head."Description: ".$desc."Place: ".$place;
                }
                // Close statement
                $stmt->close();

                // Close connection
                $mysqli->close();   

if($success) {
    echo "Selected Succesfull";
} else {
    echo "Failed: " .  $stmt->error;
  }
}
?>

Answer 1

执行该代码时应该给出错误：

参数编号无效：没有绑定参数

您需要在使用占位符时绑定参数

$stmt->bind_param("sss", $headline, $description, $place); //missing from your code

其中＆＃34; sss＆＃34;在这种情况下，dataType是一个字符串，$headline, $description, $place是您用占位符替换的变量

您的代码应为

<?php

$stmt = $mysqli->prepare("SELECT * FROM fantasies WHERE headline = ? AND description = ? AND place = ? ORDER BY reg_date DESC LIMIT 3");

//bind parameters
$stmt->bind_param("sss", $headline, $description, $place);

if ($stmt->execute()) {
    $stmt->bind_result($head, $desc, $plac);

    while ($stmt->fetch()) {

        echo "Headline: " . $head . "desc: " . $desc . "Place: " . $plac;
    }
    $stmt->close();
} else {

    echo "error" . $mysqli->error;
}

$mysqli->close();

?>

MySQl和PHP中的绑定参数

1 个答案: