如何獲得對多列值的數據匹配在同一個表

Question

我如何得到那些屬於國家79和筆者80和出版商的圖書編號91

SELECT id FROM books WHERE ( 
    (filter = 'country' AND cat = 79) 
     AND 
    (filter = 'author' AND cat = 80) 
     AND 
    (filter = 'publisher' AND cat = 91) 
    ) 

這裏是我的表結構

+----+----------+-----+ 
| ID | FITER | CAT | 
+----+----------+-----+ 
| 1 | country | 79 | 
| 1 | author | 80 | 
| 1 | publisher| 91 | 
| 2 | country | 476 | 
| 2 | author | 85 | 
| 2 | publisher| 121 | 
+----+----------+-----+   

謝謝

Answer 1

這是這種表結構的問題，你真的有那麼多的過濾器，他們不能對自己列？無論如何，這將是這樣的：

SELECT DISTINCT id 
FROM books b 
WHERE filter = 'country' AND cat = 79 
AND EXISTS(SELECT 1 FROM books 
      WHERE filter = 'author' AND cat = 80 
      AND id = b.id) 
AND EXISTS(SELECT 1 FROM books 
      WHERE filter = 'publisher' AND cat = 91 
      AND id = b.id);