while循環不能用於多個變量php？

Question

我想做一個while循環，它從Mysql數據庫中檢索所有相關數據，但它不適用於多個變量，我認爲這個問題與while循環有關，因爲我回顯了sql語句，該變量的值正確，代碼：

$wherein = implode(',', $_SESSION['cart']); 
$sql = "select ID, Name, Price from lamps WHERE ID = '$wherein'"; 
$result = mysqli_query($conn, $sql); 

echo "<table style='width:100%' border='1' >"; 
echo "<tr>"; 
echo "<th> Product Name</th>"; 
echo "<th>Product Price </th>" ; 
echo "<th>Quantity </th>" ; 
echo "</tr>"; 

while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) { 
    echo "<tr>"; 
    echo "<td>" . $row['Name'] . "</td>"; 
    echo "<td> $". $row['Price'] . "</td>" ; 
    echo "<td> <select> 
     <option value= '1'>1</option> 
     <option value= '2'>2</option> 
     <option value= '3'>3</option> 
    </select> 
    </td>"; 

    echo "</tr>"; 
} 

echo "</table>"; 

我已經嘗試了許多事情的代碼，但問題依然存在，我將非常感謝您的幫助，謝謝。

Answer 1

</table>語句位於while循環中。因此，一旦表格在第一次循環後關閉，其餘的數據可能不會顯示在瀏覽器上（它仍然會在您的html源代碼中）。嘗試將</table>語句移動到最後一行。

Answer 2

假設通過imploding變量你將有多個ID，那麼你應該在SQL中使用IN語句。

$wherein = implode("','", $_SESSION['cart']); 
$sql = "select ID, Name, Price from lamps WHERE ID IN ('$wherein')"; 

呈現的輸出可以稍微簡化，表格應該在循環後關閉！不知道的內容$wherein使得它棘手的回答，但我會認爲IN說法似乎符合一個逗號分隔值的性質在查詢中使用比直接等號=

$wherein = implode("','", $_SESSION['cart']); 
$sql = "select ID, Name, Price from lamps WHERE ID IN ('$wherein')"; 
$result= mysqli_query($conn, $sql); 

echo " 
    <table style='width:100%' border='1' > 
     <tr> 
      <th> Product Name</th> 
      <th>Product Price </th> 
      <th>Quantity </th> 
     </tr>"; 

while ($row = mysqli_fetch_object($result)){ 
    echo " 
     <tr> 
      <td>{$row->Name}</td> 
      <td>${$row->Price}</td> 
      <td> 
       <select> 
        <option value= '1'>1 
        <option value= '2'>2 
        <option value= '3'>3 
       </select>   
      </td> 
     </tr>"; 
} 
echo " 
    </table>"; 


/* Example of using an array of IDs and imploding to generate where conditions for IN clause */ 

$cart=array('BGL1','BJL'); 
/* session - cart */ 

$wherein=implode("','", $cart); 
/* correctly add quotes around each string */ 

$sql="select ID, Name, Price from lamps WHERE ID IN ('$wherein');"; 
/* use the new $wherein string within quotes */ 
echo $sql; 

>> select ID, Name, Price from lamps WHERE ID IN ('BGL1','BJL');