如何在sql中使用父級和子級別選擇標題？

Question

我需要搜索標題'%p%'。如果我檢查標題，父母瓦片和狀態作爲父母和孩子的水平。 如果搜索到的標題父可見，則顯示子標題。

SELECT title 
FROM table1 t1 
JOIN table1 t2 ON t1.title = t2.parenttitle AND t1.visible = TRUE 
JOIN table1 t3 ON t3.title = t2.parenttitle AND t3.visible = TRUE 
WHERE t1.title LIKE '%p%' 

表1

Title | ParentTitle|visible 
P1  Home   TRUE 
p1.1  p1   TRUE 
p1.2  p1   FALSE  
p1.3  p1.2  TRUE 
p1.3.1  p1.3  TRUE 
p2   Home  TRUE 
p2.1  p2   TRUE 
p2.2  p2.1  FALSE  
P3   Home  TRUE 
p3.1  p3   TRUE 
P3.1.1  p3.1  FALSE  

我需要輸出像

title 
p1 
p1.1 
p2 
p2.1 
P3 
p3.1 

Answer 1

CREATE TABLE CTE(
    Title VARCHAR(20), 
    ParentTitle VARCHAR(20), 
    visible VARCHAR(20),  
) 

INSERT INTO CTE 
VALUES 
('p1', 'Home', 'TRUE'), 
('p1.1', 'p1', 'TRUE'), 
('p1.2', 'p1', 'FALSE'),  
('p1.3', 'p1.2', 'TRUE'), 
('p1.3.1', 'p1.3', 'TRUE'), 
('p2', 'Home', 'TRUE'), 
('p2.1', 'p2', 'TRUE'), 
('p2.2', 'p2.1', 'FALSE'),  
('P3', 'Home', 'TRUE'), 
('p3.1', 'p3', 'TRUE'), 
('P3.1.1', 'p3.1', 'FALSE') 


; WITH YTE AS 
(
    SELECT *, 
    ROW_NUMBER() OVER(PARTITION BY LEFT(A.Title, 2) ORDER BY A.Title) AS RN, 
    DENSE_RANK() OVER(ORDER BY LEFT(A.Title, 2)) AS DR 
    FROM CTE A 
) 
, ZTE AS 
(
    SELECT *, ROW_NUMBER() OVER(PARTITION BY LEFT(A.Title, 2) ORDER BY A.Title) AS RNFalse 
    FROM YTE A 
    WHERE A.visible = 'FALSE' 
) 
, ATE AS 
(
    SELECT A.Title 
    FROM YTE A 
    INNER JOIN ZTE B ON A.DR = B.DR AND A.RN < B.RN 
    WHERE RNFalse = 1 
) SELECT * FROM ATE 

/* 
Output: 
p1 
p1.1 
p2 
p2.1 
P3 
p3.1 
*/ 

如果你不想使用公用表表達式，然後使用子查詢

SELECT A.Title FROM 
(
    SELECT *, 
    ROW_NUMBER() OVER(PARTITION BY LEFT(A.Title, 2) ORDER BY A.Title) AS RN 
    FROM CTE A 
) AS A 
INNER JOIN 
(
    SELECT *, 
    ROW_NUMBER() OVER(PARTITION BY LEFT(A.Title, 2) ORDER BY A.Title) AS RNFalse 
    FROM 
    (
     SELECT *, 
     ROW_NUMBER() OVER(PARTITION BY LEFT(A.Title, 2) ORDER BY A.Title) AS RN 
     FROM CTE A 
    ) A 
    WHERE A.visible = 'FALSE' 
) AS B ON LEFT(A.Title, 2) = LEFT(B.Title, 2) AND A.RN < B.RN 
WHERE B.RNFalse = 1 

所以，如果你想刪除ROW_NUMBER也必須比較varchar這是不好的。但沒有其他方式你離開我。試試這個，

SELECT A.Title FROM CTE A 
INNER JOIN 
(
    SELECT LEFT(Title, 2) AS TitleGroup, Min(Title) AS Title 
    FROM CTE 
    WHERE visible = 'False' 
    GROUP BY LEFT(Title, 2) 
) B ON LEFT(A.Title, 2) = B.TitleGroup 
AND A.Title < B.Title --Comparing String like this is not good