PHP MySQLi：選擇多個行並顯示每個行的選定列值

Question

我是MySQLi和PHP的新手，我想通過匹配一個postid從數據庫中選擇注釋。 它應該選擇所有具有該ID的行，並顯示每行的名稱和值。 但是沒有用。

      // Create connection
  $conn = mysqli_connect($hostname, $username, $password, $dbname);
  // Check connection
  if (!$conn) {
      die("Connection failed: " . mysqli_connect_error());
      echo "<script>alert('dead!')</script>";
  }

    $get_comments = "SELECT * FROM 'articlecomments' WHERE 'commentpost' = 'post1' LIMIT 0 , 30";
  $check_comments = mysqli_query($conn, $get_comments);

    while ( $row = mysqli_fetch_assoc($check_comments) )  {
        echo "<script>alert('we have comments!');</script>

      <div class='comment-single'>
        <div class='row'>
          <div class='col-md-3'>
            " . $check_comments['commentname'] . "
          </div>
          <div class='col-md-9'>
            " . $check_comments['commentvalue'] . "
         </div>
       </div>
      </div>
    ";

}

連接建立良好，因為我可以在同一腳本中訪問數據庫的其他部分。 我懷疑查詢有問題。

謝謝

Answer 1

使用勾號來轉義列而不是單引號：

SELECT *
FROM `articlecomments`
WHERE `commentpost` = 'post1'
LIMIT 30

Answer 2

您必須使用$row['commentname']和$row['commentvalue']從數據庫中獲取數據。

echo "<script>alert('we have comments!');</script>

  <div class='comment-single'>
    <div class='row'>
      <div class='col-md-3'>
        " . $row['commentname'] . "
      </div>
      <div class='col-md-9'>
        " . $row['commentvalue'] . "
     </div>
   </div>
  </div>
";

Answer 3

您在表格名稱周圍的單引號錯誤：

$get_comments = "SELECT * FROM 'articlecomments' WHERE 'commentpost' = 'post1' LIMIT 0 , 30";

正確的是：

$get_comments = "SELECT * FROM articlecomments WHERE commentpost = 'post1' LIMIT 0, 30";

必須寫$ row：

 " . $row['commentname'] . "
      </div>
      <div class='col-md-9'>
        " . $row['commentvalue'] . "