如何实现MySQLi嵌套的准备好的语句? [英] How to implement MySQLi nested prepared statements?

问题描述

我正在尝试将MySQL转换为MySQLi.而且我不知道为什么会刹车

I am trying to convert MySQL to MySQLi. And I cannot figure out why it brakes on

$stmt2->execute();

并返回错误:

Call to a member function execute() on a non-object

任何问题或有效实施！！

Any issue or valid implementing of it!?

// SQL condition "WHERE group=''" where `group` is empty (NULL)
$result = "SELECT id, name FROM table WHERE group='' ORDER BY array ASC";

if ($stmt = $mysqli->prepare($result)) {
    $stmt->execute();
    $stmt->bind_result($id, $name);

    while ($stmt->fetch()) {
        // SQL condition "WHERE group='$id'" where $id defined in $stmt->bind_result($id, $name);
        $result2 = "SELECT name FROM table WHERE group='$id' ORDER BY array ASC";

        $stmt2 = $mysqli->prepare($result2);
        //$valid_stmt2 = $stmt2 === FALSE ? false : true;

        echo $name . "\n";

        //if ($valid_stmt2) {
            // Error cased on $stmt2->execute();
            $stmt2->execute();
            $stmt2->bind_result($name2);

            while ($stmt2->fetch()) {
                echo 'related to: ' . $name2 . "\n";
            }

            $stmt2->close();
        //}
    }

    $stmt->free_result();
    $stmt->close();
}

此问题可能与可以使用多个/嵌套的MySQLi语句有关? 不幸的是，由于它没有提供有效的示例或问题资源，因此我认为它没有帮助.

This question might be related to Possible to use multiple/nested MySQLi statements? Unfortunately I did not find it helpful since it does not provide a valid example or resource for issue.

更新:带有注释的简化代码示例.

推荐答案

您先做

"SELECT id, url, name FROM links WHERE group='' ORDER BY array ASC"

然后您要使用$id进行操作

"SELECT url, name FROM links WHERE group='$id' ORDER BY array ASC"

如何得到结果?如果组等于空字符串，那么它将不等于$id(仅当$id也为空字符串，但这是没有意义的.)

How would get result for that? If group equal empty string, then it will not equal $id(only if $id is empty string too but that's non sense.)

这篇关于如何实现MySQLi嵌套的准备好的语句?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！