我一直在研究这个表单问题，它不会将数据插入数据库并显示错误：
完整性约束冲突：1048 列"appID"不能为空
我已经在我的$_GET['id']上运行了var_dump，它将其显示为正常传递的变量，我不知道为什么 MySQL 认为它是空的。
形式：
<?php
if ($_SESSION["loggedIn"]) { ?>
<!--//include("form.php");
echo "<a href='form.php?id=".$_GET['id']."'>Add a review</a>";-->
<form method="POST"
action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
<select name="rating">
<option value=""></option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
<span class="error"><?php echo $rateErr;?></span>
<br />
<textarea rows="4" cols="50" name="comment" value="<?php echo htmlspecialchars($comment);?>">Enter text here...</textarea>
<span class="error"><?php echo $comErr;?></span>
<input type="submit" name="submit" value="Submit">
</form>
<?php }
else {
echo "You need to login to review this app";
}
?>
以及验证和插入数据的功能
<?php
// define variables and initialize with empty values
$rateErr = $comErr = "";
$rating = $comment = "";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if ($_POST["rating"] == "") {
$rateErr = "Rate the app";
}
else {
$rating= $_POST["rating"];
}
if (empty($_POST["comment"])) {
$comErr = "Missing";
}
else {
$comment = $_POST["comment"];
}
if ($rateErr == "" && $comErr == "") {
try {
$con = new PDO( DB_DSN, DB_USERNAME, DB_PASSWORD );
$con->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
$sql = "INSERT INTO reviews (rating, content, appID, user) VALUES (:rating, :comment, :id, :username)";
$stmt = $con->prepare( $sql );
$stmt->bindValue( ":rating", $rating);
$stmt->bindValue( ":comment", $comment);
$stmt->bindValue( ":id", $_GET['id']);
$stmt->bindValue( ":username", $_SESSION['username']);
$stmt->execute();
return "Submitted successfully";
}
catch( PDOException $e ) {
echo $e->getMessage();
}
}
}
?>
如果你使用$_POST请求，你需要检查变量，更改：
if ($rateErr == "" && $comErr == "") {
自
if (empty($rateErr) && empty($comErr) && isset($_POST['id']) && !empty($_POST['id'])) {
并替换下一行，因为您没有$_GET请求：
$stmt->bindValue(":id", $_GET['id']);
自
$stmt->bindValue(":id", $_POST['id']);
您正在检查此内容;请注意POST请求方法：
if ($_SERVER["REQUEST_METHOD"] == "POST") {
但是访问这个; 注意$_GET请求方法：
$stmt->bindValue(":id", $_GET['id']);
什么时候应该使用$_POST：
$stmt->bindValue(":id", $_POST['id']);
也就是说，你有这个：
if ($_SERVER["REQUEST_METHOD"] == "POST") {
但问题是，这样做else会GET对吗？而且您在该支票中嵌套了$_GET['id'] POST对吗？那为什么不这样做：
if (in_array($_SERVER["REQUEST_METHOD"], array('POST', 'GET')) {
这样，您的支票就可以处理POST和GET方法。也许需要更大的重构才能更好地捕获错误？这是您应该尝试的轻微重构。我从if ($_SERVER["REQUEST_METHOD"] == "POST") {中删除了数据库插入逻辑，并设置了一个if ($_SERVER["REQUEST_METHOD"] == "GET") {，该也设置了一个$appID。
<?php
// define variables and initialize with empty values
$rateErr = $comErr = "";
$rating = $comment = "";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if ($_POST["rating"] == "") {
$rateErr = "Rate the app";
}
else {
$rating= $_POST["rating"];
}
if (empty($_POST["comment"])) {
$comErr = "Missing";
}
else {
$comment = $_POST["comment"];
}
}
$appID = $appIDErr = "";
if ($_SERVER["REQUEST_METHOD"] == "GET") {
if (empty($_GET["id"])) {
$appIDErr = "Missing";
}
else {
$appID = $_GET["id"];
}
}
if ($rateErr == "" && $comErr == "" && $appIDErr == "") {
try {
$con = new PDO( DB_DSN, DB_USERNAME, DB_PASSWORD );
$con->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
$sql = "INSERT INTO reviews (rating, content, appID, user) VALUES (:rating, :comment, :id, :username)";
$stmt = $con->prepare( $sql );
$stmt->bindValue( ":rating", $rating);
$stmt->bindValue( ":comment", $comment);
$stmt->bindValue( ":id", $appID);
$stmt->bindValue( ":username", $_SESSION['username']);
$stmt->execute();
return "Submitted successfully";
}
catch( PDOException $e ) {
echo $e->getMessage();
}
}
?>