【发布时间】：2015-01-12 07:25:19
【问题描述】：
我一直在尝试创建一个投票系统，该系统对数据库运行查询，如果找到匹配项，则不包含该答案。
这是一个投票系统，当用户对投票进行投票时，它将 pollid 和 userid 存储在数据库表中，然后在他们重新访问页面时检索它，因此不会显示他们之前投票的投票。
我会尽力解释，我发现自己很难理解。
在我的 Pollsdone（投票和完成投票的用户 ID 所在的位置）表中，它包含 2 行和 2 列。
这两行是：
花粉
用户名
pollsdone 的两列是（用户 ID 无关紧要）：
26、用户名
76、用户名
SQL：
$sql = "SELECT * FROM Polls";
$completedVoteSearch = "SELECT * FROM Pollsdone WHERE userid='10'";
当我使用时：
foreach ($db->query($sql) as $row) {
foreach ($db->query($completedVoteSearch) as $done) {
if ($done['pollid'] != $row['pollid']) {
// CREATE POLL CODE
它将对数据库运行查询并正确选择匹配的。问题是，即使它与“76,76”匹配，它也会选择像“44,76”这样的投票并显示民意调查“76”
希望这张照片可以帮助您更好地理解它：（不是说“我们有比赛！”并且仍然显示民意调查）
http://i.stack.imgur.com/NfTLS.png
它仍然显示民意调查，即使它应该因为其他查询而被隐藏，我该如何阻止它？ 任何帮助将不胜感激！
这是我使用的代码（仅供参考，没有错误，不需要“调试”）
try {
$db = new PDO("mysql:host=$mysql_host;dbname=$mysql_db", $mysql_user, $mysql_pass);
$sql = "SELECT * FROM Polls";
$completedVoteSearch = "SELECT * FROM Pollsdone WHERE userid='10'";
foreach ($db->query($sql) as $row) {
foreach ($db->query($completedVoteSearch) as $done) {
if ($done['pollid'] == $row['pollid']) {
echo "We have a match!";
}
if ($done['pollid'] != $row['pollid']) {
echo "<br/>";
echo $done['pollid'] . ", ";
echo $row['pollid'] . ", ";
echo "<br/>";
$pollid = $row['pollid'];
$title = $row['title'];
$type = $row['type'];
if ($type == "s") {
$type = "radio";
} else {
$type = "checkbox";
}
$option1 = $row['option1'];
$option2 = $row['option2'];
$option3 = $row['option3'];
$option4 = $row['option4'];
$option5 = $row['option5'];
$option6 = $row['option6'];
$option1vote = $row['option1vote'];
$option2vote = $row['option2vote'];
$option3vote = $row['option3vote'];
$option4vote = $row['option4vote'];
$option5vote = $row['option5vote'];
$option6vote = $row['option6vote'];
$option1voteColumn = "option1vote";
$option2voteColumn = "option2vote";
$option3voteColumn = "option3vote";
$option4voteColumn = "option4vote";
$option5voteColumn = "option5vote";
$option6voteColumn = "option6vote";
}
}
// $isCompleteSQL = "SELECT * FROM Pollsdone WHERE userid='10' ";
// if ()
if (strlen($option3) < 1 && strlen($option2) > 0) {
echo '<div class="userPoll">
<div class="pollTitle">
<h3 class="pollHeader">' . $title . ' (ID = ' . $pollid . ')</h3>
</div>
<div class="pollContent">
<p class="pollSubTitle">Created By <a href="profile.php">Username</a></p>
<form class="poll" method="POST" action="mypolls.php">
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'" value="option1vote"><p class="pollAnswerText">' . $option1 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'" value="option2vote"><p class="pollAnswerText">' . $option2 . '</p></label><br/>
<input type="submit" class="pollSubmit btn btn-default"/>
</form>
</div>
</div>';
if ($_POST[$pollid] . $pollid == $option1voteColumn . $pollid) {
$option1vote = ($option1vote + 1);
$voteSQL = "UPDATE Polls SET ".$option1voteColumn."='".$option1vote."' WHERE pollid='".$pollid."'";
$db->exec($voteSQL);
}
}
if (strlen($option4) < 1 && strlen($option3) > 0) {
echo '<div class="userPoll">
<div class="pollTitle">
<h3 class="pollHeader">' . $title . ' (ID = ' . $pollid . ')</h3>
</div>
<div class="pollContent">
<p class="pollSubTitle">Created By <a href="profile.php">Username</a></p>
<form class="poll" method="POST" action="mypolls.php">
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option1 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option2 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option3 . '</p></label><br/>
<input type="submit" class="pollSubmit btn btn-default"/>
</form>
</div>
</div>';
}
if (strlen($option5) < 1 && strlen($option4) > 0) {
echo '<div class="userPoll">
<div class="pollTitle">
<h3 class="pollHeader">' . $title . ' (ID = ' . $pollid . ')</h3>
</div>
<div class="pollContent">
<p class="pollSubTitle">Created By <a href="profile.php">Username</a></p>
<form class="poll" method="POST" action="mypolls.php">
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option1 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option2 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option3 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option4 . '</p></label><br/>
<input type="submit" class="pollSubmit btn btn-default"/>
</form>
</div>
</div>';
}
if (strlen($option6) < 1 && strlen($option5) > 0) {
echo '<div class="userPoll">
<div class="pollTitle">
<h3 class="pollHeader">' . $title . ' (ID = ' . $pollid . ')</h3>
</div>
<div class="pollContent">
<p class="pollSubTitle">Created By <a href="profile.php">Username</a></p>
<form class="poll" method="POST" action="mypolls.php">
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option1 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option2 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option3 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option4 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option5 . '</p></label><br/>
<input type="submit" class="pollSubmit btn btn-default"/>
</form>
</div>
</div>';
}
if (strlen($option6) > 0) {
echo '<div class="userPoll">
<div class="pollTitle">
<h3 class="pollHeader">' . $title . ' (ID = ' . $pollid . ')</h3>
</div>
<div class="pollContent">
<p class="pollSubTitle">Created By <a href="profile.php">Username</a></p>
<form class="poll" method="POST" action="mypolls.php">
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option1 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option2 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option3 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option4 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option5 . '</p></label><br/>
<label><input type="' . $type . '" class="pollAnswer" name="'. $pollid .'"><p class="pollAnswerText">' . $option6 . '</p></label><br/>
<input type="submit" class="pollSubmit btn btn-default"/>
</form>
</div>
</div>';
}
}$db = null;
} catch(PDOException $e) {
$e->getMessage();
}
【问题讨论】：
-
什么是
44,76，什么是76,76？你试图达到的主要目标是什么？不显示用户已经参与的投票？select * from Polls where pollid NOT IN (select pollid from polldone where user_id = 10) -
这可能行得通。我会尝试并在之前给它@U_mulder！
-
然后我收到错误“警告：第 70 行 [..loc..] 中为 foreach() 提供的参数无效” foreach 为：
foreach ($db->query($sql) as $row)，SQL 为：@ 987654329@ -
不，抱歉。我只是错误地复制了您的 SQL，它可以完美运行并且使用的代码更少。创建一个答案，您将成为第一名！ :) 非常感谢！
标签： php mysql if-statement foreach