如何在mysql中獲取id

Question

這是顯示建築物的所有樓層，我想顯示選定的建築物樓層我怎麼能這樣做我使用這個鏈接floors.php？id = Building1但它不工作請幫助我

如果我寫在那裏它號樓工作正常where buildingname='building1'

，如果我用這一個where buildingname='$id'它不工作

我怎麼可以使用這樣

floors.php？ID =號樓

，如果我進入這個鏈接，然後它會顯示所有選定的建築結果

<?php 
    $max_results = 8; 

    $from = (($page * $max_results) - $max_results); 


    if(empty($_POST)) { 
        $query = "SELECT * FROM floors where buildingname='$id' ORDER BY floorno ASC LIMIT $from, $max_results "; 
    } 
    $result = mysql_query("SET NAMES utf8"); //the main trick 
    $result = mysql_query($query) or die(mysql_error()); 
    $rows = mysql_num_rows($result); 

    $count=0; 
    while($row = mysql_fetch_array($result)) 
     { 
      if($count%4==0) 
      { 
      echo "<tr/>"; 
      echo "<tr>"; 
      } 

      echo "<td><div align='center'><img src='images/floor.gif' width='60' height='90'></a><p>" . $row['floorno'] . "</p><div></td>"; 

      $count++; 


    } 



    echo "</tr>"; 
    echo "</table>"; 
    echo '</div>'; 
    ?> 

Answer 1

if(empty($_POST)) { 
    $query = "SELECT * FROM floors where buildingname='$id' ORDER BY floorno ASC LIMIT $from, $max_results "; 
} 

右邊是：

if (isset($_GET['id'])) { 
    $id = filter_input(INPUT_GET, 'id'); 
    $query = "SELECT * FROM floors where buildingname='$id' ORDER BY floorno ASC LIMIT $from, $max_results "; 
} 

Answer 2

，可以幫助你。

<?php 
    $id =isset($_GET['id'])?$_GET['id']:null; // here you put value in $id only if it has some value. 
    $max_results = 8; 

    $from = (($page * $max_results) - $max_results); 


    if($id != null) { 
     $query = sprintf("SELECT * FROM floors WHERE buildingname='%s' ORDER BY floorno ASC LIMIT $from, $max_results", mysql_real_escape_string($id)); // safe from sql injection 
     $result = mysql_query("SET NAMES utf8"); //the main trick 
     $result = mysql_query($query) or die(mysql_error()); 
     $rows = mysql_num_rows($result); 


     $count=0; 
     while($row = mysql_fetch_array($result)) 
     { 
     if($count%4==0) 
     { 
     echo "<tr/>"; 
     echo "<tr>"; 
     } 

     echo "<td><div align='center'><img src='images/floor.gif' width='60' height='90'></a><p>" . $row['floorno'] . "</p><div></td>"; 

     $count++; 
     } 
    } 


    echo "</tr>"; 
    echo "</table>"; 
    echo '</div>'; 
?>