每次页面刷新时都不会检索来自 mysql 的数据

Question

我试图从 mysql 数据库中获取随机数据，但它只在页面刷新时获取同一行我尝试运行查询以从 mysql 获取随机单行数据并使用 php 在网页上显示，但它每次只检索同一行 $sql = "SELECT * FROM identity_explorer_demographics ORDER BY RAND() LIMIT 1<?php$link = mysqli_connect("host", "username", "password", "db_name");if($link === false){    die("ERROR: Could not connect. " . mysqli_connect_error());}$sql = "SELECT * FROM identity_explorer_demographics ORDER BY RAND() LIMIT 1";if($result = mysqli_query($link, $sql)){    if(mysqli_num_rows($result) > 0){        echo "<table>";            echo "<tr>";                echo "<th>email_md5</th>";                echo "<th>age_group </th>";                echo "<th>age</th>";                echo "<th>income</th>";                echo "<th>Income_group </th>";                echo "<th>gender</th>";            echo "</tr>";        while($row = mysqli_fetch_array($result)){            echo "<tr>";                echo "<td>" . $row['email_md5'] . "</td>";                echo "<td>" . $row['age_group'] . "</td>";                echo "<td>" . $row['age'] . "</td>";                echo "<td>" . $row['income'] . "</td>";                 echo "<td>" . $row['Income_group'] . "</td>";                echo "<td>" . $row['gender'] . "</td>";            echo "</tr>";        }        echo "</table>";        // Free result set        mysqli_free_result($result);    } else{        echo "No records matching your query were found.";    }} else{    echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);}// Close connectionmysqli_close($link);?>每次刷新页面时，我都需要显示随机行数据。如果有人可以建议是最佳解决方案，那真的会很有帮助。

Answer 1

你把它和 PHP 混在一起

$sql = 'SELECT * FROM `identity_explorer_demographics`';

//Perform query and parse result, E.G $sql = db::query($sql);

function getRandomRow($sql) {

   $random_row = count(0, count($sql));

   foreach($sql as $row => $result) {

      if ($row == $random_row) {

         return $row;

      }

   }

}

Answer 2

$sql = "SELECT * FROM identity_explorer_demographics ORDER BY RAND() LIMIT 1";

将行更改为

$ randomv = rand (min, max);

$sql = "SELECT * FROM identity_explorer_demographics ORDER BY $randomv LIMIT 1";

这是我在另一种情况下的实现，我必须从可用的随机 id 中进行选择 - Yii 2 Framework

   $prodcutids= \app\models\TblProduct::find()->all();

    $targetproduct=  ArrayHelper::map($prodcutids, 'id','id');

    $productdetails= \app\models\TblProduct::findOne(['id'=>array_rand($targetproduct)]);

    $productseriesname= \app\models\TblSeries::findOne(['id'=>$productdetails['Serie']]);

或者，如果您有一个 id 列

$sql = "SELECT * FROM identity_explorer_demographics WHERE id=$randomv LIMIT 1";

rand(min,max) min 指定将返回的最小值。max 指定要返回的最大值。