我的頁面顯示圖像,我想顯示與當前圖像相關的上一張和下一張圖像。目前我運行相同的查詢3x並修改"where"
語句=, >, <
。我該如何優化這個mysql/php查詢?
它的作品,但我覺得必須有一個更好的方式來做到這一點。
圖片ID不是1,2,3,4,5。可能是1,2,10,20,21等。但如果效率更高,我願意改變這一點。
mysql_select_db("database", $conPro);
$currentid = mysql_real_escape_string($_GET['currentid']);
$query ="SELECT * FROM database WHERE id ='".$currentid."' LIMIT 1 ";
$result = mysql_query($query,$conPro) or die(mysql_error());
$affected_rows = mysql_num_rows($result);
if ($affected_rows==1)
{
$row = mysql_fetch_array($result)or die ('error:' . mysql_error());
$current_id = $row['id'];
$current_header = $row['title'];
$current_description =$row['desc'];
$current_image = "http://".$row['img'];
$current_url = "http://".$row['id']."/".$db_title."/";
$current_thumb = "http://".$row['cloud'];
}
mysql_select_db("database", $conPro);
$query ="SELECT * FROM database WHERE id <'".$currentid."' ORDER BY id DESC LIMIT 1 ";
$result = mysql_query($query,$conPro) or die(mysql_error());
$affected_rows = mysql_num_rows($result);
if ($affected_rows==1)
{
$row = mysql_fetch_array($result)or die ('error:' . mysql_error());
$previous_id = $row['id'];
$previous_header = $row['title'];
$previous_description =$row['desc'];
$previous_image = "http://".$row['img'];
$previous_url = "http://".$row['id']."/".$db_title."/";
$previous_thumb = "http://".$row['cloud'];
}else{
$previous_none = "true"; //no rows found
}
mysql_select_db("database", $conPro);
$query ="SELECT * FROM database WHERE id >'".$currentid."' ORDER BY id ASC LIMIT 1 ";
$result = mysql_query($query,$conPro) or die(mysql_error());
$affected_rows = mysql_num_rows($result);
if ($affected_rows==1)
{
$row = mysql_fetch_array($result)or die ('error:' . mysql_error());
$next_id = $row['id'];
$next_header = $row['title'];
$next_description =$row['desc'];
$next_image = "http://".$row['img'];
$next_url = "http://".$row['id']."/".$db_title."/";
$next_thumb = "http://".$row['cloud'];
}else{
$next_none = "true"; //no rows found
}
mysql_close($conPro);
謝謝您的時間
而不是做比運營商更少/更大的將有可能使用平等。我想@Shaune可以回答這個問題。如果是這樣,則**和**限制**的**順序可以被移除。另外,是否有yourtable.id索引? – 2012-01-14 09:13:07