我在找出下面的代码的while和foreach循环中在做什么时遇到了一些主要困难。我倾向于混合使用面向对象和过程性的mqsqli,但是每次我认为正确时,都会出错。
在这段代码中的循环中我在做什么错?
现在我得到这个错误
Warning: mysqli::query() expects parameter 1 to be string,
完整代码
try {
$con = new mysqli("localhost", "", "", "");
if (mysqli_connect_errno()) {
throw new Exception("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$cid = $_GET['cid'];
$tid = $_GET['tid'];
$userid = ( isset( $_SESSION['user'] ) ? $_SESSION['user'] : "" );
echo $cid . "<br>";
echo $tid;
//Prepare
if ($stmt = $con->prepare("SELECT * FROM forum_topics WHERE `category_id`=? AND `id`=? LIMIT 1")) {
$stmt->bind_param("ii", $cid, $tid);
//$stmt->fetch();
if (!$stmt) {
throw new Exception($con->error);
}
}
$stmt->store_result();
$numrows = $stmt->num_rows;
if($numrows == 1){
echo "<table width='100%'>";
if ( $_SESSION['user'] ) {
echo "<tr><td colspan='2'><input type='submit' value='Add Reply' onclick=\"window.location =
'forum_post_reply.php?cid=".$cid."$tid=".$tid."'\"> <hr />";
} else {
echo "<tr><td colspan='2'><p>Please log in to add your reply</p><hr /></td></tr>";
}
foreach($stmt as $row) {
//Prepared SELECT stmt to get forum posts
if($stmt2 = $con->prepare("SELECT * FROM forum_posts WHERE `category_id`=? AND `topic_id`=?")) {
//var_dump($stmt2);
$stmt2->bind_param("ii", $cid, $tid);
$stmt2->execute();
}
if ($result = $con->query($stmt)) {
while ($row2 = $result->fetch_assoc() ) {
echo "<tr><td valign='top' style='border: 1px solid #000000;'>
<div style='min-height: 125px;'>".$row['topic_title']."<br />
by ".$row2['post_creator']." - " .$row2['post_date']. "<hr />" . $row2['post_content'] ."</div></td>
<td width='200' valign='top' align='center' style='border: 1px solid #000000;'>User Info Here!</td></tr>
<tr><td colspan='2'><hr /></td></tr>";
}
}
}
} else {
echo "<p>This topic does not exist.</p>";
}
最佳答案
if ($stmt = $con->prepare("SELECT * FROM forum_topics WHERE `category_id`=? AND `id`=? LIMIT 1")) {
$stmt->bind_param("ii", $cid, $tid);
//$stmt->fetch();
if (!$stmt) {
throw new Exception($con->error);
}
}
$stmt->store_result();
$numrows = $stmt->num_rows;
在遍历
$stmt
之前,您实际上根本没有执行过foreach($stmt as $row) {
。您将要把它扔在那里:
$stmt->execute()
您的逻辑遍布各处。您看起来好像遍历了从未执行过的查询结果,然后尝试在此处重新查询原始的
$stmt
:if ($result = $con->query($stmt)) {
编辑:与您聊天后,您需要编辑原始查询以查询特定列,以便可以像这样引用它们:
if ($stmt = $con->prepare("SELECT topic_creator FROM forum_topics WHERE `category_id`=? AND `id`=? LIMIT 1")) {
...
$stmt->bind_result($topic_creator);
while ($stmt->fetch()) {
echo "TC: " . $topic_creator . "<br>";
}
您可以将其应用于
while
循环中的子查询。关于php - 在带循环的预备语句后发出输出数据,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/31570715/