遞歸查詢標籤？

我有一個標籤表可以鏈接到其他標籤，我想「遞歸」按順序選擇標籤。因此，當進行搜索時，我們得到立即（1級）結果，然後繼續說5級，這樣我們總是有一個標籤列表，無論1級上是否有足夠的精確匹配遞歸查詢標籤？

我可以通過多次查詢來處理這個問題，直到獲得足夠的結果爲止，但通過一次查詢確實存在更好的優化方式嗎？

任何提示將不勝感激。謝謝！

結果：

tagId, tagWord, child, child tagId 
'513', 'Slap', 'Hog Slapper', '1518' 
'513', 'Slap', 'Corporal Punishment', '147' 
'513', 'Slap', 'Impact Play', '1394'

查詢：

SELECT t.tagId, t.tagWord as tag, tt.tagWord as child, tt.tagId as childId 

FROM platform.tagWords t 

INNER JOIN platform.tagsLinks l ON l.parentId = t.tagId 
INNER JOIN platform.tagWords tt ON tt.tagId = l.tagId 

WHERE t.tagWord = 'slap'

表佈局：

mysql> explain tagWords; 
+---------+---------------------+------+-----+---------+----------------+ 
| Field | Type    | Null | Key | Default | Extra   | 
+---------+---------------------+------+-----+---------+----------------+ 
| tagId | bigint(20) unsigned | NO | PRI | NULL | auto_increment | 
| tagWord | varchar(45)   | YES | UNI | NULL |    | 
+---------+---------------------+------+-----+---------+----------------+ 
2 rows in set (0.00 sec) 

mysql> explain tagsLinks; 
+----------+---------------------+------+-----+---------+-------+ 
| Field | Type    | Null | Key | Default | Extra | 
+----------+---------------------+------+-----+---------+-------+ 
| tagId | bigint(20) unsigned | NO |  | NULL |  | 
| parentId | bigint(20)   | YES |  | NULL |  | 
+----------+---------------------+------+-----+---------+-------+ 
2 rows in set (0.00 sec)

來源

2010-12-20 Matthew Brandon Davis