我希望根据表number上x列中的最大数量获取行的x。
例如：
我在 id | number
---------+---------
9 | 289
10 | 100
24 | 187
54 | 345
表中有以下记录。
id我希望查询返回SELECT x.id ... 54 （number），发现列<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" dir="RTL" lang="Ar">
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<link href="css/style.css" media="screen" rel="stylesheet" type="text/css" />
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="refresh" content="30">
</head>
<body>
<form method= "POST" action = "" >
<?php include ("connection.php"); ?>
<?php
$msg = "";
if (isset($_POST['update'])) {
if (is_numeric($_POST['question_id'])) {
$question_id = mysqli_real_escape_string($link, htmlspecialchars($_POST['question_id']));
$question_text = mysqli_real_escape_string($link, htmlspecialchars($_POST['question_text']));
$test_id = mysqli_real_escape_string($link, htmlspecialchars($_POST['test_id']));
if ($question_text == "" || $test_id == "" ) {
$msg = "يرجى تعبيئة كافة الحقول";
} else {
$sql = mysqli_query($link, " UPDATE `question` SET `question_text`='".$question_text."',`test_id`= '".$test_id."'
WHERE `question_id` = '".$question_id."' ")or die(mysqli_error($link));
/* UPDATE `question` SET `question_text`='".."',`test_id`= '".."' WHERE `question_id` = */
}
} else {
echo "Error !";
}
}else {
if (isset($_GET['question_id']) && is_numeric($_GET['question_id']) && $_GET['question_id'] > 0) {
$question_id = $_GET['question_id'];
$query = mysqli_query($link, "SELECT * FROM `question` WHERE `question_id` = '".$question_id."' ")
or die(mysqli_error($link));
$isFirst = TRUE;
while ($row = mysqli_fetch_assoc($query)) {
$question_id = $row ['question_id'];
$question_text = $row ['question_text'];
$test_id = $row['test_id'];
if ($isFirst) {
?>
<p>
<label>رقم الاختبار</label>
<td><input type="text" name="test_id" value="<?php echo $test_id ; ?>" /></td>
</p>
<?php
$isFirst = FALSE;
}
?>
<p>
<label><p>الحقل المخصص للسؤال</p></label>
<textarea name = "question_text"><?php echo $question_text ; ?> </textarea>
</p>
<?php
$query2 = mysqli_query($link,"SELECT * FROM `answers` WHERE answers.question_id = '".$question_id."' ") or die(mysqli_error($link));
while($row2 = mysqli_fetch_assoc($query2)){
$answer_text = $row2 ['answer_text'];
$correct = $row2 ['correct'];
/*
SELECT question.question_id,question.question_text,question.test_id,test.test_name
FROM question,test
WHERE question.test_id = test.test_id
AND question.question_id= '".$question_id."'
*/
/* SELECT `answer_text`, `correct` FROM `answers` WHERE answers.question_id = 6 AND answers.correct = 1 */
?>
<p>
<label>الخيار الاول</label>
<input type="text" name="" value="<?php echo $answer_text ; ?>" />
</p>
<?php
}
?>
<p>
<input type="submit" name="update" value="تحديث البيانات" class="button save" />
</p>
<p>
<input type="hidden" name = "question_id" value="<?php echo $_GET['question_id']; ?>" />
</p>
<?php
}
}
}
?>
</form>
</body>
</html>
的最大值为345 < /强>
我怎样才能成功呢？
答案 0 :(得分：1)
请尝试以下查询：
解决方案＃1：
SELECT
x.*
FROM x
INNER JOIN
(
SELECT
MAX(number) AS max_number
FROM x
) AS maxTable
ON x.number = maxTable.max_number
<强>解释
SELECT
MAX(number) AS max_number
FROM x;
结果：
<强> maxTable：
max_number
345
现在在inner join和x上的maxTable表与maxTable.max_number上面的x.number之间建立一个 =====================
| id | number |
=====================
| 9 | 289 |
---------------------
| 10 | 100 |
---------------------
| 24 | 187 |
---------------------
| 54 | 345 |
---------------------
。
x table：
maxTable.max_number因此，在最终输出中，您只会获得number列中WHERE IN的条目。
解决方案＃2：
您也可以使用SELECT
*
FROM x
WHERE x.number IN ( SELECT MAX(number) FROM x )
来完成此任务。
WrapWholeWords答案 1 :(得分：0)
为什么你不这样做：
select t.id
from t
order by number desc
limit 1;