php 如何在 PDO fetchAll 中正确使用 while 循环
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how to properly use while loop in PDO fetchAll
提问by bobbyjones
please be easy on me, i just started learning PDO and still finding my way how to convert my mysqli to PDO.
请对我放轻松，我刚开始学习 PDO 并且仍在寻找如何将我的 mysqli 转换为 PDO 的方法。
so i have a function to get the contents from my database
所以我有一个函数可以从我的数据库中获取内容
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;
}
normally when i return $rowin mysqli, i would define fetch_assoc()in my while loop.
通常当我$row在 mysqli 中返回时，我会fetch_assoc()在我的 while 循环中定义。
while ($row = $result->fetch_assoc()) {
$id = $row['id'];
$content = $row['content'];
}
Now, since (PDO::FETCH_ASSOC)is already declared in my function.
现在，因为(PDO::FETCH_ASSOC)已经在我的函数中声明了。
how would i properly create my whileloop to print the values in PDO?
我将如何正确创建while循环以打印 PDO 中的值？
[edit] updated code
[编辑] 更新代码
i will be declaring my whileloop outside of the function. so i need something to return from my function but i dont know what that is..
我将while在函数之外声明我的循环。所以我需要一些东西从我的函数中返回，但我不知道那是什么..
function getContent() {
$db = PDOconn();
$query = "SELECT * FROM posts ORDER BY id DESC LIMIT 0,3";
$sql = $db->prepare($query);
$row = $sql->execute();
return $row;
}
this is my while loop outside the function.
这是我在函数外的 while 循环。
$sql = getContent();
while ($row = $sql->fetchAll(PDO::FETCH_ASSOC)) {
$id = $row['id'];
$content = $row['content'];
}
回答by Hanky Panky
With fetchAll()you don't have to use whileat all. As this function returns an array, you have to use foreach()instead:
有了fetchAll()你根本不必使用while。由于此函数返回一个数组，因此您必须foreach()改用：
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'];
}
