我目前的疑问。我可以将它们合并为较少以获得相同的结果?我正试图将有关轨迹的特定信息放入名为$ trail的数组中。是否有更有效的方法来编写这4个MYSQL查询以使用更少的查询?
$result = mysql_query("SELECT meta_value FROM wp_postmeta WHERE `post_id` = $id AND `meta_key` = 'location_city' ");
$result = mysql_fetch_array($result);
$trail[city] = $result[0];
$result = mysql_query("SELECT meta_value FROM wp_postmeta WHERE `post_id` = $id AND `meta_key` = 'length' ");
$result = mysql_fetch_array($result);
$trail[length] = $result[0];
$result = mysql_query("SELECT meta_value FROM wp_postmeta WHERE `post_id` = $id AND `meta_key` = 'location_state' ");
$result = mysql_fetch_array($result);
$trail[state] = $result[0];
$result = mysql_query("SELECT meta_value FROM wp_postmeta WHERE `post_id` = $id AND `meta_key` = 'difficulty' ");
$result = mysql_fetch_array($result);
$trail[difficulty] = $result[0];
$result = mysql_query("SELECT guid FROM wp_posts WHERE `post_parent` = $id AND `post_type` = 'attachment' ");
$result = mysql_fetch_array($result);
$trail[image] = $result[0];
是,使用或OR为meta_key – 2013-01-22 18:41:26
你有没有试图合并查询?如果这样向我们展示你的尝试。你要求做的是技术上可行的。此外,4个查询与1个查询的性能完全取决于您设置的索引。通常,主键查找速度非常快,因此您不会看到性能上的巨大差异。 – Dean
您应该切换到'error_reporting(E_ALL);'现在,然后修复所有通知。例如,引用你的数组键! – ThiefMaster