准备一部分准备好的陈述失败 - 直接在另一份准备好的陈述下

时间：2015-07-20 13:09:46

标签： php mysql mysqli prepared-statement

我准备了一个失败的准备好的声明...... 

$stmt2 = $con->prepare("SELECT * FROM forum_posts WHERE `category_id`=? AND `topic_id`=?");
    //var_dump($stmt2);
    if ( !$stmt2 || !empty($con->error)) {
        die('Select forum posts prepare() failed: ' . htmlspecialchars($con->error));
    }

我在我的第一份准备好的声明中几乎完全相同，并且它完成得很好。我不确定如果这导致问题或者情况如何，我是否有两个相互准备好的陈述？

现在我收到了这个错误......

- 选择论坛帖子prepare（）失败： -

上述代码中的准备失败错误。

有没有人看到任何导致此失败的事情？

$con = mysqli_connect("localhost", "root", "", "db");
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
$cid = $_GET['cid'];
$tid = $_GET['tid'];
$userid = ( isset( $_SESSION['user'] ) ? $_SESSION['user'] : "" );

//Prepared SELECT stmt to get forum topics
$stmt = $con->prepare("SELECT * FROM forum_topics WHERE `category_id`=? AND id=? LIMIT 1");
if (!$stmt || $con->error ) {
    die('Select topics prepare() failed: ' . htmlspecialchars($con->error));
}
if(!$stmt->bind_param('ii', $cid, $tid)) {
    die('Select topics bind_param() failed: ' . htmlspecialchars($stmt->error));
}
if(!$stmt->execute()) {
    die('Select topics execute() failed: ' . htmlspecialchars($stmt->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
        $stmt2 = $con->prepare("SELECT * FROM forum_posts WHERE `category_id`=? AND `topic_id`=?");
        //var_dump($stmt2);
        if ( !$stmt2 || !empty($con->error)) {
            die('Select forum posts prepare() failed: ' . htmlspecialchars($con->error));
        }
        //var_dump($con->error);
        if(!$stmt2->bind_param('ii', $cid, $tid)) {
            die('Select forum posts bind_param() failed: ' . htmlspecialchars($stmt2->error));
        }
        if(!$stmt2->execute()) {
            die('Select forum posts execute() failed: ' . htmlspecialchars($stmt2->error));
        }
        //while($row2 = mysqli_fetch_assoc($stmt2)){
        foreach($stmt2 as $row2) {  
            echo "<tr><td valign='top' style='border: 1px solid #000000;'>
            <div style='min-height: 125px;'>".$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>";
}

更新 - 可能的INNER JOIN，像这样吗？

//Prepared SELECT stmt to get forum topics
$stmt = $con->prepare("SELECT * FROM forum_topics AS f INNER JOIN forum_posts AS p ON
 f.category_id=p.category_id ON f.id=p.topic_id WHERE s.category_id=? AND s.id=? LIMIT 1");
if (!$stmt || $con->error ) {
    die('Select topics prepare() failed: ' . htmlspecialchars($con->error));
}
if(!$stmt->bind_param('ii', $cid, $tid)) {
    die('Select topics bind_param() failed: ' . htmlspecialchars($stmt->error));
}
if(!$stmt->execute()) {
    die('Select topics execute() failed: ' . htmlspecialchars($stmt->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 $row) {
            echo "<tr><td valign='top' style='border: 1px solid #000000;'>
            <div style='min-height: 125px;'>".$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>";
}

}*/
/*$stmt = $con->prepare("SELECT topic_title, post_content FROM forum_topics, forum_posts 
WHERE forum_topics.category_id=forum_posts.category_id 
AND forum_topics.category_id=?");*/
//$stmt = $con->prepare("SELECT topic_title, topic_creator FROM forum_posts AS f LEFT JOIN forum_topics AS p ON f.category_id=p.category_id WHERE f.category_id=?");
$stmt = $con->prepare("SELECT topic_title, topic_creator FROM forum_posts AS p, forum_topics AS f WHERE f.category_id=? AND p.topic_id=? LIMIT 1");
if (!$stmt || $con->error ) { 
die('Select forum prepare() failed: ' . htmlspecialchars($con->error)); 
} 
if(!$stmt->bind_param('ii', $cid, $tid)) { 
die('Select forum bind_param() failed: ' . htmlspecialchars($stmt->error)); 
}
if(!$stmt->execute()) { 
die('Select forum execute() failed: ' . htmlspecialchars($stmt->error)); 
}
mysqli_stmt_bind_result($stmt, $post_content, $topic_title); 
$stmt->store_result(); 
echo $stmt->store_result(); 
$numrows = $stmt->num_rows; 
if($stmt->num_rows > 0){
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>";
}
while (mysqli_stmt_fetch($stmt)) {
echo "<tr><td valign='top' style='border: 1px solid #000000;'> 
<div style='min-height: 125px;'>".$topic_title."<br /> 
by " . $post_content ."</div></td> 
<td width='200' valign='top' align='center' style='border: 1px solid #000000;'>User Info Here!</td></tr> 
<tr><td colspan='2'><hr /></td></tr>";
} 
mysqli_stmt_close($stmt); 
} else { 
echo "<p>This topic does not exist.</p>"; 
}

?>
    </body>
</html>

1 个答案:

答案 0 :(得分：2)

在OP中花了5个小时聊天，最后解决问题

问题;

  • 第二次查询失败
  • 第一个查询结果未显示

没有必要;

  • 无需加入表格
  • 无需第二次选择查询
  • 没有foreach

解; 

//bind the result
mysqli_stmt_bind_result($stmt, $topic_title, $topic_creator, $postDate, $postcontent);
//use while loop instead foreach
while (mysqli_stmt_fetch($stmt))

工作代码; 

//Prepared SELECT stmt to get forum topics
$stmt = $con->prepare("SELECT topic_title, topic_creator, post_date, post_content FROM forum_posts AS p, forum_topics AS f WHERE f.category_id=? AND p.topic_id=?");
if (!$stmt || $con->error ) {
    die('Select forum prepare() failed: ' . htmlspecialchars($con->error));
}
if(!$stmt->bind_param('ii', $cid, $tid)) {
    die('Select forum bind_param() failed: ' . htmlspecialchars($stmt->error));
}
if(!$stmt->execute()) {
    die('Select forum execute() failed: ' . htmlspecialchars($stmt->error));
}
mysqli_stmt_bind_result($stmt, $topic_title, $topic_creator, $postDate, $postcontent);
$stmt->store_result();
if($stmt->num_rows > 0){

    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>";
    }
    while (mysqli_stmt_fetch($stmt)) {
        echo "<tr><td valign='top' style='border: 1px solid #000000;'>
        <div style='min-height: 125px;'>".$topic_title."<br />
        by ".$topic_creator." - " .$postDate. "<hr />" . $postcontent ."</div></td>
        <td width='200' valign='top' align='center' style='border: 1px solid #000000;'>User Info Here!</td></tr>
        <tr><td colspan='2'><hr /></td></tr>";
        }
        mysqli_stmt_close($stmt);
} else {
    echo "<p>This topic does not exist.</p>";
}

忘了提一下，这是我第一次使用mysqli，我读过它但从未尝试过。

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