我会这样做
function get_inserts ($db, $id) {
$base_sql = "SELECT c.categoryID,
c.parent,
IFNULL(c.custom_inserts_ru, p.custom_inserts_ru) custom_inserts_ru,
p.parent parent_parent
FROM SC_categories c LEFT JOIN
SC_categories p ON c.parent = p.categoryID
WHERE c.categoryID=";
$inserts = "";
do {
$result = mysql_query ($base_sql . $id, $db);
if (!$result) break;
$row = mysql_fetch_assoc($result);
$inserts = $row['custom_inserts_ru'];
$id = $row['parent_parent'];
} while (strlen($inserts) == 0 && $id);
if($result) {
mysql_free_result ($result);
}
return $inserts;
}
减少后续查询的数量引入了自连接类别的深层树,可以从当前类别或从其直接父元素中选取值custom_inserts_ru
。
要使用它
$mycat = 1146;
$db = mysql_connect(...);
if (!$db) {
die('Not connected : ' . mysql_error());
}
$db_selected = mysql_select_db('test', $db);
if (!$db_selected) {
die ('Unable to select database : ' . mysql_error());
}
$inserts = get_inserts($db, $mycat);
echo "custom_inserts_ru for Id $currentID is '$inserts'";
mysql_close($db);
由于mysql_*
扩展deprecated,你最好切换到PDO或MySQLi和使用prepared statements。
代码的缩进不正确。为什么在“其他”部分的“endwhile”?它的目的是? – Jocelyn 2013-03-20 00:30:17
找到结果时如何正确停止? – skywind 2013-03-20 00:31:51