如何在PDO fetchAll中正确使用while循环 [英] how to properly use while loop in PDO fetchAll

问题描述

请放心，我才刚刚开始学习PDO，仍然在寻找将mysqli转换为PDO的方法.

please be easy on me, i just started learning PDO and still finding my way how to convert my mysqli to PDO.

所以我有一个从数据库中获取内容的功能

so i have a function to get the contents from my database

function getContent() {
    $db = PDOconn();
    $query = "SELECT * FROM posts ORDER BY id DESC LIMIT 0,3";
    $sql = $db->prepare($sql);
    $row = $sql->fetchAll(PDO::FETCH_ASSOC);

    return $row;
}

通常，当我在mysqli中返回$row时，我会在while循环中定义fetch_assoc().

normally when i return $row in mysqli, i would define fetch_assoc() in my while loop.

while ($row = $result->fetch_assoc())  {
    $id = $row['id'];
    $content = $row['content'];
}

现在，因为在我的函数中已经声明了(PDO::FETCH_ASSOC).

Now, since (PDO::FETCH_ASSOC) is already declared in my function.

我将如何正确创建我的while循环以在PDO中打印值?

how would i properly create my while loop to print the values in PDO?

更新的代码

[edit] updated code

我将在函数外部声明我的while循环.所以我需要一些可以从我的函数中返回的东西，但是我不知道那是什么.

i will be declaring my while loop outside of the function. so i need something to return from my function but i dont know what that is..

function getContent() {
    $db = PDOconn();
    $query = "SELECT * FROM posts ORDER BY id DESC LIMIT 0,3";
    $sql = $db->prepare($query);
    $row = $sql->execute();

    return $row;
}

这是我在函数外的while循环.

this is my while loop outside the function.

$sql = getContent();

while ($row = $sql->fetchAll(PDO::FETCH_ASSOC))  {
    $id = $row['id'];
    $content = $row['content'];
}

推荐答案

使用fetchAll() ，您完全不必使用while .当此函数返回一个 array 时，您必须使用foreach()代替:

With fetchAll() you don't have to use while at all. As this function returns an array, you have to use foreach() instead:

function getContent() {
    $db = PDOconn();
    $query = "SELECT * FROM posts ORDER BY id DESC LIMIT 0,3";
    $sql = $db->prepare($query);
    $sql->execute();
    return $sql->fetchAll();
}

$data = getContent();
foreach($data as $row) {
    $id = $row['id'];
    $content = $row['content'];
}

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