SQL Right Join問題

Question

我的查詢進行了正確加入，但結果不正確。
Null值必須在列NAME_2等於A，我無法弄清楚什麼是錯的。

下面是該查詢：

http://sqlfiddle.com/#!6/cd45b/1

對於未來的讀者。表的定義：

CREATE TABLE S1 (TIME_1 DateTIME, INTERVAL_1 INT, NAME_1 varchar(20),INITIAL_VAL int); 
CREATE TABLE S2 (TIME_2 DateTIME, INTERVAL_2 INT, NAME_2 varchar(20), FINAL_VAL int); 

相關問題的數據插入：

INSERT INTO S1 values('10.02.2017 00:00',1, 'B',13); 
INSERT INTO S1 values('10.02.2017 01:00',2, 'B',14); 
INSERT INTO S1 values('10.02.2017 02:00',3, 'B',10); 
INSERT INTO S1 values('10.02.2017 03:00',4, 'B',15); 

INSERT INTO S1 values('10.02.2017 00:00',1, 'C',42); 
INSERT INTO S1 values('10.02.2017 01:00',2, 'C',10); 
INSERT INTO S1 values('10.02.2017 02:00',3, 'C',22); 
INSERT INTO S1 values('10.02.2017 03:00',4, 'C',18); 


INSERT INTO S2 values('10.02.2017 00:00',1, 'A',12); 
INSERT INTO S2 values('10.02.2017 01:00',2, 'A',13); 
INSERT INTO S2 values('10.02.2017 02:00',3, 'A',9); 
INSERT INTO S2 values('10.02.2017 03:00',4, 'A',16); 

INSERT INTO S2 values('10.02.2017 00:00',1, 'B',16); 
INSERT INTO S2 values('10.02.2017 01:00',2, 'B',22); 
INSERT INTO S2 values('10.02.2017 02:00',3, 'B',20); 
INSERT INTO S2 values('10.02.2017 03:00',4, 'B',10); 

INSERT INTO S2 values('10.02.2017 00:00',1, 'C',42); 
INSERT INTO S2 values('10.02.2017 01:00',2, 'C',15); 
INSERT INTO S2 values('10.02.2017 02:00',3, 'C',22); 
INSERT INTO S2 values('10.02.2017 03:00',4, 'C',19); 

初始查詢從這樣一個問題：

WITH CTE1 
AS 
(
    SELECT ROW_NUMBER() OVER (ORDER BY NAME_1) AS V1, * FROM S1 
) 
,CTE2 
AS 
(
    SELECT ROW_NUMBER() OVER (ORDER BY NAME_2) AS V2,* FROM S2 
) 
SELECT 
CTE2.NAME_2, 
CTE2.TIME_2, 
INTERVAL_2, 
CTE1.INITIAL_VAL, 
CTE2.FINAL_VAL 
FROM CTE1 
RIGHT JOIN CTE2 
ON CTE1.V1=CTE2.V2 

Answer 1

你的右連接是匹配了生產ROW_NUMBER。因此，NAME_2值：A與NAME_1值沒有匹配。

從表S1與B從表S2匹配A，因爲他們都得到同樣的ROW_NUMBER

請運行該看的時候你做正確的加入什麼是匹配：

SELECT ROW_NUMBER() OVER (ORDER BY NAME_1) AS V1, * FROM S1; 
SELECT ROW_NUMBER() OVER (ORDER BY NAME_2) AS V2,* FROM S2; 

編輯： 回答你的問題從評論。這是很難確切地知道你需要建立什麼，但我認爲，時間間隔可能會帶來一些有趣的結果：

WITH CTE1 
AS 
(
    SELECT ROW_NUMBER() OVER (ORDER BY NAME_1) AS V1, * FROM S1 
) 
,CTE2 
AS 
(
    SELECT ROW_NUMBER() OVER (ORDER BY NAME_2) AS V2,* FROM S2 
) 
SELECT 
CTE2.NAME_2, 
CTE2.TIME_2, 
INTERVAL_2, 
CTE1.INITIAL_VAL, 
CTE2.FINAL_VAL 
FROM CTE1 
RIGHT JOIN CTE2 
ON CTE1.NAME_1=CTE2.NAME_2 AND CTE1.INTERVAL_1 = CTE2.INTERVAL_2 

Answer 2

是區間始終同爲NAME_1和NAME_2？否則它會再次出錯。不知道您是否只需要名稱列或名稱組合&區間的連接。如果Jakub Szumiato給出的答案已經適用於您，請忽略。我採用了一個簡單的測試數據，並用Jakub Szumiato給出的查詢執行。這是輸出。