問題描述

我盡量不感到沮喪，但我最近了解到 mysql_* 在 PHP 中已被棄用.我決定學習如何使用 PDO.

I'm trying not to get frustrated, but I've recently learned that mysql_* is deprecated in PHP. I've decided that I would learn how to use PDO.

今天下午我剛剛在看它，使用它連接到數據庫很容易，但后來我想用它獲取一行并將該行保存為由列名索引的數組(同樣的方式正如函數 mysql_fetch_array 所做的那樣).我想不出它來挽救我的生命.

I've just been looking at it this afternoon, and connecting to the database using it was easy, but then I wanted to fetch a row with it and save the row as an array indexed by the column names (the same way as the function mysql_fetch_array did). I can't figure it out to save my life.

我會發布我的代碼來澄清，我確信它很簡單(所有編程錯誤總是很簡單)，但我肯定做錯了什么.

I'll post my code to clarify, and I'm sure it is something simple (all programming errors are always simple), but I am definitely doing something wrong.

// Connect to the database
$host    = $_PARAM["DatabaseServer"];
$db        = $_PARAM["MainDatabase"];
$dbuser    = $_PARAM["DatabaseUser"];
$dbpass    = $_PARAM["DatabasePass"];
try
{
    $Database = new PDO("mysql:host=$host;dbname=$db", $dbuser, $dbpass);
}
catch (PDOException $e)
{
    echo "There was an unexpected error. Please try again, or contact us with concerns";
}

$stmt = $Database->prepare("SELECT * FROM users WHERE username=?");
$stmt->execute(array($sUserCook));
$row = $stmt->fetchAll(PDO::FETCH_ASSOC);

echo $row["username"];

推薦答案

fetchAll 做它所說的:它獲取查詢的所有結果.由于它獲取了大量結果，因此您將獲得一個索引數組.

fetchAll does what it says: it fetches all results for a query. Since it fetches a lot of results, you'll get an indexed array.

fetch 會執行您可能正在尋找的操作:它為查詢獲取一個結果.如果您要將 mysql_* 代碼轉換為 PDO，最快的方法是使用此方法而不是 mysql_fetch_assoc.

fetch does what you might be looking for if you want only one row: it fetches one result for a query. If you're converting mysql_* code to PDO, the quickest way would be to just use this method instead of mysql_fetch_assoc.

如果您仍然使用 fetchAll:您的代碼可能看起來像這樣:

If you're still going with fetchAll: your code would probably just look like this:

$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
foreach ($rows as $row) {
    echo $row['username'];
}

就像我說的，如果您只是將遺留代碼轉換為 PDO 代碼，將所有查詢更改為準備好的語句并替換以下內容可能會更容易:

Like I said, if you're just converting legacy code to PDO code, it might be easier to just change all queries to prepared statements and replace the following:

• mysql_fetch_assoc($result)
  -> $stmt->fetch(PDO::FETCH_ASSOC)
• mysql_num_rows($result)
  -> $stmt->rowCount()
• while ($row = mysql_fetch_assoc($result)) {}
  -> foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {}

這篇關于如何使用 PDO 獲取一行的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！