从函数返回关联数组(Return associative array from function)

这就是我通常用数据库信息运行循环的方法

$query = "SELECT * from courses ORDER BY id DESC LIMIT 4"; $stmt = $db->prepare($query); $stmt->execute(); while($row = $stmt->fetch(PDO::FETCH_ASSOC)) { }

现在$row[]可用于表示循环内的数据库信息。

我的问题是，我会在单独的while循环中大量使用这个查询。但是，我不希望每次需要时都要完成此语句，因此我希望函数能够引用所需的任何变量。

例如，我试过了。

function retrieve_assoc_array_limit4($table) { $user = '***'; $pass = '***'; $db = new PDO('mysql:host=localhost;dbname=***', $user, $pass); $query = ("SELECT * FROM ? ORDER BY id DESC LIMIT 4"); $stmt = $db->prepare($query); $stmt->bindValue(?, $table); $stmt->execute(); $row = $stmt->fetch(PDO::FETCH_ASSOC); return $row; }

但是当我试图在它的同时获得无限量的相同信息的回报时。

while($row = retrieve_assoc_array_limit4($table_name)) { exho $data; }

我的问题是如何在逻辑上使用函数中的第一个代码，这样我就可以在不使用完整语句的情况下使用它。

This is how I would normally run a loop with database information

$query = "SELECT * from courses ORDER BY id DESC LIMIT 4"; $stmt = $db->prepare($query); $stmt->execute(); while($row = $stmt->fetch(PDO::FETCH_ASSOC)) { }

Now $row[] can be used to represent database information within the loop.

My problem is that I'll be utilizing this query a lot for separate while loops. However, I don't wish to have to complete this statement every time I require it, so I want a function to be able to refer to with any variables required.

For instance, I tried.

function retrieve_assoc_array_limit4($table) { $user = '***'; $pass = '***'; $db = new PDO('mysql:host=localhost;dbname=***', $user, $pass); $query = ("SELECT * FROM ? ORDER BY id DESC LIMIT 4"); $stmt = $db->prepare($query); $stmt->bindValue(?, $table); $stmt->execute(); $row = $stmt->fetch(PDO::FETCH_ASSOC); return $row; }

But when trying to while it I get an unlimited amount of returns of the same information whiled.

while($row = retrieve_assoc_array_limit4($table_name)) { exho $data; }

My question is how logically to use the first code in a function so that I can use it in the same with without writing out the full statement relentlessly.

最满意答案

许多方法，使用您的代码几乎没有变化：

调用fetchAll（）而不是fetch（）：

function retrieve_assoc_array_limit4($table) { $user = '***'; $pass = '***'; $db = new PDO('mysql:host=localhost;dbname=***', $user, $pass); $query = ("SELECT * FROM ? ORDER BY id DESC LIMIT 4"); $stmt = $db->prepare($query); $stmt->bindValue(?, $table); $stmt->execute(); $rows = $stmt->fetchAll(PDO::FETCH_ASSOC); return $rows; }

然后打电话给你的功能，做一会儿或做一些事情：

$rows = retrieve_assoc_array_limit4($table_name); foreach($rows as $row){ //do your stuff }

many ways of doing this, to use your code with little changes:

calling fetchAll() instead of fetch():

function retrieve_assoc_array_limit4($table) { $user = '***'; $pass = '***'; $db = new PDO('mysql:host=localhost;dbname=***', $user, $pass); $query = ("SELECT * FROM ? ORDER BY id DESC LIMIT 4"); $stmt = $db->prepare($query); $stmt->bindValue(?, $table); $stmt->execute(); $rows = $stmt->fetchAll(PDO::FETCH_ASSOC); return $rows; }

then call your function and do a while or foreach:

$rows = retrieve_assoc_array_limit4($table_name); foreach($rows as $row){ //do your stuff }

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