使用bindParam与PDO

Question

我一直在抓我的头在此代码为几个小时.... 没有道理给我，为什么它不工作

$isCorrect =($question->correct_answer == $body->answer) ? 1:0; 
// the values are all there....... 
// echo $body->question . "\n"; //335 
// echo $body->user . "\n";  //51324123 
// echo $question->day . "\n"; //0 
// echo $isCorrect . "\n";  //0 

//but still the below part fails. 
$db = getConnection(); 
$sql = "INSERT INTO `answers` (`id`, `question_id`, `user`, `day`, `is_correct`) VALUES (NULL, ':question', ':user', ':day', :is_correct)"; 
$stmt = $db->prepare($sql); 
$stmt->bindParam(":question_id", $body->question); 
$stmt->bindParam(":user", $body->user); 
$stmt->bindParam(":day", $question->day, PDO::PARAM_INT); 
$stmt->bindParam(":is_correct", $isCorrect, PDO::PARAM_INT); 
$stmt->execute(); 

给出了这样的错误：

SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens 

我在计算4个标记...我错过了什么？显然我做错了什么。

Answer 1

变化：

$stmt->bindParam(":question_id", $body->question); 

到：

$stmt->bindParam(":question", $body->question); 

您在查询:question使用，但用错了键（:question_id）结合。

Answer 2

$stmt->bindParam(":question_id", $body->question); 

应该

$stmt->bindParam(":question", $body->question); 

这只是一个小错字。

Answer 3

只是不使用bindParam和PDO
以及命名参数。它会为你节省大量的头痛

$db = getConnection(); 
$sql = "INSERT INTO `answers` VALUES (NULL, ?,?,?,?)"; 
$data = [$body->question,$body->user,$question->day,$isCorrect]; 
$stmt = $db->prepare($sql)->execute($data); 

Answer 4

试试这样说：

$sql = "INSERT INTO `answers` (`id`, `question_id`, `user`, `day`, `is_correct`) 
     VALUES 
     --The :variable shouldn't be surrounded by ''-- 
     (NULL, :question, :user, :day, :is_correct)"; 
$stmt = $db->prepare($sql); 
//The values used in $sql should be the same here, so not :question_id but :question 
$stmt->bindParam(":question", $body->question); 
$stmt->bindParam(":user", $body->user); 
$stmt->bindParam(":day", $question->day, PDO::PARAM_INT); 
$stmt->bindParam(":is_correct", $isCorrect, PDO::PARAM_INT);