Oracle SQL查詢 - 需要幫助

Question

對於下面的Table結構，我無法構建所需的輸出，不確定是否需要應用轉置，但我沒有很強的知識。 最後給出了用於表創建和數據插入的SQL腳本。

輸出格式應如上所示，輸出結果的ID_MAX_VAL應爲主源表中每個製造商國家組合的ID的最大值。我需要獲取每個製造商國家/地區組合的最大ID，並顯示/使用它們發送報告。

輸出：

MANUFACTURER COUNTRY  ID_MAX_VAL 
-------------------------------------- 
NISSAN   USA   10 
NISSAN   UK   30 
HONDA   USA   80 
HONDA   UK   70 

注：這是一個測試數據和表結構來模擬實際的業務需求。

與我剛纔提到的表格類似的視圖是我們唯一可以訪問的東西，並且可以作爲我們的唯一來源。只能使用它。

SQL腳本：

CREATE TABLE TB_TEST_01 
(
    ID NUMBER(6) NOT NULL 
, PARAM_NM VARCHAR2(200) NOT NULL 
, PARAM_VAL VARCHAR2(200) 
); 
/

INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (10, 'MANUFACTURER', 'NISSAN'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (10, 'COUNTRY', 'USA'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (30, 'MANUFACTURER', 'NISSAN'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (30, 'COUNTRY', 'UK'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (20, 'MANUFACTURER', 'NISSAN'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (20, 'COUNTRY', 'UK'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (50, 'MANUFACTURER', 'HONDA'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (50, 'COUNTRY', 'USA'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (60, 'MANUFACTURER', 'HONDA'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (60, 'COUNTRY', 'USA'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (80, 'MANUFACTURER', 'HONDA'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (80, 'COUNTRY', 'USA'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (70, 'MANUFACTURER', 'HONDA'); 
INSERT INTO TB_TEST_01 (ID, PARAM_NM, PARAM_VAL) VALUES (70, 'COUNTRY', 'UK') 
; 
/
COMMIT; 

Answer 1

在沒有標準化的設計的情況下，我們可以自行參加表，就像下面的一樣。

SELECT T1.PARAM_VAL AS MANUFACTURER, 
     T2.PARAM_VAL AS COUNTRY, 
     MAX(T1.ID) AS MAX_ID_VAL 
FROM TB_TEST_01 T1,TB_TEST_01 T2 
WHERE 
     T1.ID = T2.ID 
    AND T1.PARAM_NM='MANUFACTURER' 
    AND T2.PARAM_NM='COUNTRY' 
GROUP BY 
    T1.PARAM_VAL,T2.PARAM_VAL 

Answer 2

試試這個

CREATE TABLE TB_TEST_01 
(
    ID NUMBER(6) NOT NULL 
, MANUFACTURER VARCHAR2(200) NOT NULL 
, COUNTRY VARCHAR2(200) 
); 
/

INSERT INTO TB_TEST_01 (ID, MANUFACTURER, COUNTRY) VALUES (10, 'NISSAN', 'USA'); 
INSERT INTO TB_TEST_01 (ID, MANUFACTURER, COUNTRY) VALUES (20, 'NISSAN', 'UK'); 
INSERT INTO TB_TEST_01 (ID, MANUFACTURER, COUNTRY) VALUES (30, 'NISSAN', 'UK'); 
INSERT INTO TB_TEST_01 (ID, MANUFACTURER, COUNTRY) VALUES (50, 'HONDA', 'USA'); 
INSERT INTO TB_TEST_01 (ID, MANUFACTURER, COUNTRY) VALUES (60, 'HONDA', 'USA'); 
INSERT INTO TB_TEST_01 (ID, MANUFACTURER, COUNTRY) VALUES (70, 'HONDA', 'UK'); 
INSERT INTO TB_TEST_01 (ID, MANUFACTURER, COUNTRY) VALUES (80, 'HONDA', 'USA'); 

COMMIT; 
/

和出把

SELECT manufacturer, country,MAX(ID) id_max FROM TB_TEST_01 
GROUP BY manufacturer,country; 

Answer 3

可以使用PIVOT功能也：

select M_PARAM_VAL MANUFACTURER, C_PARAM_VAL COUNTRY, max(ID) ID_MAX_VAL 
    from TB_TEST_01 
pivot (min(PARAM_VAL) as PARAM_VAL for (PARAM_NM) in ('MANUFACTURER' as M, 'COUNTRY' as C)) 
group by M_PARAM_VAL, C_PARAM_VAL; 

輸出：

| MANUFACTURER | COUNTRY | ID_MAX_VAL | 
|--------------|---------|------------| 
|  HONDA |  UK |   70 | 
|  NISSAN |  USA |   10 | 
|  NISSAN |  UK |   30 | 
|  HONDA |  USA |   80 | 

Answer 4

@San @OracleUser 感謝所有幫助，並與不同類型的解決方案.. PIVOT ，SELF JOIN .. :) （我是PIVOT的新手，仍然需要了解它是如何工作的）

我用它像這樣得到一個特定製造商的詳細信息：

SELECT T1.PARAM_VAL AS MANUFACTURER, 
     T2.PARAM_VAL AS COUNTRY, 
     MAX(T1.ID) AS MAX_ID_VAL 
FROM TB_TEST_01 T1,TB_TEST_01 T2 
WHERE 
     T1.ID = T2.ID 
    AND T1.PARAM_NM='MANUFACTURER' 
    AND T2.PARAM_NM='COUNTRY' 
    AND T1.PARAM_VAL='HONDA' 
GROUP BY 
    T1.PARAM_VAL,T2.PARAM_VAL;