Question

我正在尝试在PDO中查询我的数据库并在表单上输出。但是fetch语句不起作用。代码是

try {
include '../../config/database.php';
$database = new Database();
$db = $database->getConnection();


//prepare query
$query = "select 
            payment_id, payment_supplier, payment_ref, payment_cost_rating, payment_amount 
        from 
            payments 
        where 
            payment_id = ? 
        limit 0,1";

$stmt = $db->prepare( $query );

//this is the first question mark
$stmt->bindParam(1, $_REQUEST['myData']);

//execute our query
if($stmt->execute()){
var_dump($stmt->fetch());
    //store retrieved row to a variable
    $row = $stmt->fetch(PDO::FETCH_ASSOC); 

    //values to fill up our form
    $payment_id = $row['payment_id'];
    $payment_supplier = $row['payment_supplier'];
    $payment_ref = $row['payment_ref'];
    $payment_cost_rating = $row['payment_cost_rating'];
    $payment_amount = $row['payment_amount'];

}else{
    echo "Unable to read record.";
}

}

var_dump ($stmt); prints

object(PDOStatement)#3 (1) { ["queryString"]=> string(157) "select payment_id, payment_supplier, payment_ref, payment_cost_rating, payment_amount from payments where payment_id = ? limit 0,1" }

但fetch()总是返回false。这是包含的database.php文件，如果它有帮助

class Database{

// database credentials
private $host = "localhost";
private $db_name = "test-project";
private $username = "root";
private $password = "";
public $conn;

// get the database connection
public function getConnection(){

    $this->conn = null;

    try{
        $this->conn = new PDO("mysql:host=" . $this->host . ";dbname=" . $this->db_name, $this->username, $this->password);
    }catch(PDOException $exception){
        echo "Connection error: " . $exception->getMessage();
    }

    return $this->conn;
}}

我在这里缺少什么？

Answer 1

添加执行结果检查并查看错误：

if($stmt->execute()){
    ...
}else{
    echo "Unable to read record:". print_r($stmt->errorInfo(), true);
}

Answer 2

的问题是与取指被使用两次。

可以通过以下方式完成：

这应该很好。

使用PDO fetch查询Mysql返回false

2 个答案: