如何加入來自多個SQL查詢的結果

Question

我想顯示在SELECT中定義的所需列，一旦執行了一個條件並打印條件的結果，我想從SELECT中的新指定列中顯示另一個條件條款等等，首先不知何故，我需要解決這兩個查詢，之後，該計劃是混合約10個queires。感謝詩的是，i_di1.naziv

SELECT bolnickiracun.id, 
     bolnickiracun.id_dijagnoza1, i_di1.naziv naziv_dijagnoza1 
FROM  bolnickiracun 
LEFT JOIN i_dijagnoze_marko i_di1 ON bolnickiracun.id_dijagnoza1=i_di1.id 
WHERE bolnickiracun.id_dijagnoza1!="" and i_di1.naziv is null 
UNION ALL 
SELECT bolnickiracun.id, 
     bolnickiracun.id_dijagnoza2, i_di2.naziv naziv_dijagnoza2 
FROM  bolnickiracun 
LEFT JOIN i_dijagnoze_marko i_di2 ON bolnickiracun.id_dijagnoza2=i_di2.id 
WHERE bolnickiracun.id_dijagnoza2!="" and i_di2.naziv is null 

我想結果是這樣的結果，一切都顯示在列的問題之一：

id id_dijagnoza1 naziv_dijagnoza1 id_dijagnoza2 naziv_dijagnoza2 
1  some data   null    
2  some data   null 
3          some data   null 
4          some data   null 

點是要找到naziv_dijagnoza1或naziv_dijagnoza2哪裏是空即，外鍵顯示不存在主鍵，或者某人導入不存在作爲主鍵的錯誤外鍵。

Answer 1

這個例子對於3 SELECT（第三個通過基於可以看到的模式的推論預測）應該有助於理解對於整個查詢需要做什麼10 SELECT's。您需要在每個SELECT之後的每個列中填寫NULL的SELECT子句。

SELECT bolnickiracun.id, bolnickiracun.id_dijagnoza1, i_di1.naziv naziv_dijagnoza1, NULL, NULL, NULL, NULL -- and so on 
FROM  bolnickiracun 
LEFT JOIN i_dijagnoze_marko i_di1 ON bolnickiracun.id_dijagnoza1=i_di1.id 
WHERE bolnickiracun.id_dijagnoza1!="" and i_di1.naziv is null 

UNION ALL 

SELECT bolnickiracun.id, NULL, NULL, bolnickiracun.id_dijagnoza2, i_di2.naziv naziv_dijagnoza2, NULL, NULL -- and so on 
FROM  bolnickiracun 
LEFT JOIN i_dijagnoze_marko i_di2 ON bolnickiracun.id_dijagnoza2=i_di2.id 
WHERE bolnickiracun.id_dijagnoza2!="" and i_di2.naziv is null 

UNION ALL 

SELECT bolnickiracun.id, NULL, NULL, NULL, NULL, bolnickiracun.id_dijagnoza3, i_di3.naziv naziv_dijagnoza3 -- and so on 
FROM  bolnickiracun 
LEFT JOIN i_dijagnoze_marko i_di3 ON bolnickiracun.id_dijagnoza3=i_di3.id 
WHERE bolnickiracun.id_dijagnoza3!="" and i_di3.naziv is null 

列的每SELECT數應是相同的，因爲你可以看到，對於3 SELECTš它的7列（每2表接合×3個SELECT S + 1與ID第一列）。對於每個SELECT條款中的每個012條中的21列（1代表id，2代表每個表中，其餘的填充NULL s）。 不是漂亮的解決方案，但可能只有像這樣的數據庫結構。

所以對於10 SELECT的弗里斯特最後應該是這樣的：

SELECT bolnickiracun.id, bolnickiracun.id_dijagnoza1, i_di1.naziv naziv_dijagnoza1, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL 
FROM  bolnickiracun 
LEFT JOIN i_dijagnoze_marko i_di1 ON bolnickiracun.id_dijagnoza1=i_di1.id 
WHERE bolnickiracun.id_dijagnoza1!="" and i_di1.naziv is null 

UNION ALL 
... 
UNION ALL 

SELECT bolnickiracun.id, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, bolnickiracun.id_dijagnoza10, i_di10.naziv naziv_dijagnoza10 
FROM  bolnickiracun 
LEFT JOIN i_dijagnoze_marko i_di10 ON bolnickiracun.id_dijagnoza10=i_di10.id 
WHERE bolnickiracun.id_dijagnoza10!="" and i_di10.naziv is null