从SQL Query获取结果

时间:2013-07-14 11:26:29

标签: php sql

我根据船舶信息数据库获得了MySQL查询,其中包括字段ship_name和密钥ship_id

我已经编写了一个使用页面current_ship_id的查询,并根据ship_names的字母顺序列表查找下一艘船。

这一切都很好,但是,我尝试使用以下代码创建一个链接?' IF'声明。

header("Location: shipinfo.php?ship_id=$next_ship_id"); 

我不知道该怎么做才是定义变量next_ship_id。我试过这行:

$next_ship_id = ($ship_id);

理论上,我想得到查询$sql的结果(其中我知道只有一个结果)并找到它ship_id

我该怎么做?

$sql = "    SELECT ship_infomation.ship_id
              FROM   ship_infomation
        INNER JOIN (
                  SELECT ship_name 
                    FROM   ship_infomation
                   WHERE  ship_id = $current_ship_id
                   ) As current_ship
                ON ship_infomation.ship_name < current_ship.ship_name
          ORDER BY ship_infomation.ship_name ASC
             LIMIT 1";

// echo "<br /><br />$sql<br /><br />";
$ships = mysql_query($sql, $ships) or die(mysql_error());
$row_ships = mysql_fetch_assoc($ships);
$totalRows_ships = mysql_num_rows($ships);
$next_ship_id = ($ship_id);
if ($totalRows_ships = 1)
{
    header("Location: shipinfo.php?ship_id=$next_ship_id");
}
else
{
    // remain on current page  
}

1 个答案:

答案 0 :(得分:0)

对于下一次使用船舶:

SELECT ship_id 
  FROM ship_infomation 
 WHERE ship_id = (SELECT min(ship_id) 
                    FROM ship_infomation 
                   WHERE ship_id > $current_ship_id) 
 LIMIT 1

对于之前的船舶使用:

SELECT ship_id 
  FROM ship_infomation 
 WHERE ship_id = (SELECT max(ship_id) 
                    FROM ship_infomation 
                   WHERE ship_id < $current_ship_id) 
 LIMIT 1

在您的代码中更改此内容:

$ships = mysql_query($sql, $ships) or die(mysql_error());
$row_ships = mysql_fetch_assoc($ships);
$totalRows_ships = mysql_num_rows($ships);
$next_ship_id = ($ship_id);
if ($totalRows_ships = 1)
{
    header("Location: shipinfo.php?ship_id=$next_ship_id");
}
else
{
    // remain on current page  
}

对此:

$ships = mysql_query($sql, $ships) or die(mysql_error());
$row = mysql_fetch_assoc($ships);
$totalRows_ships = mysql_num_rows($ships);
if ($totalRows_ships = 1)
{
    header("Location: shipinfo.php?ship_id=" . $row['ship_id']);
}
else
{
    // remain on current page  
}

对于您的代码中的下一个和上一个:

$go = isset($_GET['go']) ? $_GET['go'] : 'next';
if ($go == 'next')
    $sql = "SELECT ship_id FROM ship_infomation WHERE ship_id = (SELECT min(ship_id) FROM ship_infomation WHERE ship_id > ". mysql_real_escape_string($current_ship_id) . ") LIMIT 1";
else
    $sql = "SELECT ship_id FROM ship_infomation WHERE ship_id = (SELECT max(ship_id) FROM ship_infomation WHERE ship_id < ". mysql_real_escape_string($current_ship_id) . ") LIMIT 1";

在你的网址上,下一艘船就是这样的:

http://mysite.com/ships.php?current_ship_id=15&go=next

和上一个一样:

http://mysite.com/ships.php?current_ship_id=15&go=previous

如果未指定go,则默认情况下将转到上一个货船。


mysql_*个功能不再支持,它们为officially deprecated不再维护,将为removed个未来。您应该使用PDOMySQLi更新代码,以确保将来的项目功能。