重複行

Question

我有以下查詢：

SELECT word, count 
FROM t_word t 
JOIN t_counter tc 
ON t.word_id = tc.id 

將會產生類似：

'cab', 2 
'capital', 3 
'new york', 2 

我想要做什麼，是有結果顯示如下：

'cab', 
'cab' 
'capital', 
'capital', 
'capital', 
'new york', 
'new york' 

因此，計數列實際上爲我的查詢重複該行。我不完全確定這是否可能，因爲我在MySQL中沒有玩過太多循環......任何指導都非常感謝！

Answer 1

Select T.word 
From t_word As T 
    Join (
      Select 1 As Num 
      Union All Select 2 
      Union All Select 3 
      ) As Numbers 
     On Numbers.Num <= T.count 

如果count實際上來自counter表，那麼你會做這樣的事情：

Select T.word 
From t_word As T 
    Join t_counter As TC 
     On TC.id = t.word_id 
    Join (
      Select 1 As Num 
      Union All Select 2 
      Union All Select 3 
      ) As Numbers 
     On Numbers.Num <= TC.count