如何在PHP中通过PDO遍历MySQL查询？

Question

我正在慢慢地将所有功能LAMP websites从一个mysql_功能移到PDO另一个功能，并且遇到了第一个障碍。我不知道如何通过参数遍历结果。我对以下内容满意：

foreach ($database->query("SELECT * FROM widgets") as $results)
{
   echo $results["widget_name"];
}

但是，如果我想做这样的事情：

foreach ($database->query("SELECT * FROM widgets WHERE something='something else'") as $results)
{
   echo $results["widget_name"];
}

显然，“其他”是动态的。

Answer 1

这是一个使用PDO连接到数据库，告诉它引发Exception（而不是php错误）（将帮助您调试）以及使用参数化语句而不是将动态值替换为查询本身的示例（强烈建议）：

// $attrs is optional, this demonstrates using persistent connections,
// the equivalent of mysql_pconnect
$attrs = array(PDO::ATTR_PERSISTENT => true);

// connect to PDO
$pdo = new PDO("mysql:host=localhost;dbname=test", "user", "password", $attrs);

// the following tells PDO we want it to throw Exceptions for every error.
// this is far more useful than the default mode of throwing php errors
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

// prepare the statement. the place holders allow PDO to handle substituting
// the values, which also prevents SQL injection
$stmt = $pdo->prepare("SELECT * FROM product WHERE productTypeId=:productTypeId AND brand=:brand");

// bind the parameters
$stmt->bindValue(":productTypeId", 6);
$stmt->bindValue(":brand", "Slurm");

// initialise an array for the results 
$products = array();
if ($stmt->execute()) {
    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
        $products[] = $row;
    }
}

// set PDO to null in order to close the connection
$pdo = null;