SQL選擇和案例相結合

Question

我在選擇語句時遇到問題，不確定我做錯了什麼。這是源表的結構：

源架構DATA1

源表FOLDERS

源列FOLDERID，USERID

目標架構DATA1

目標表FOLDER_USER

目標列FOLDER_ID，USER_ID

這裏是查詢（我需要更改文件夾ID，因爲它是被拉出第一個查詢，因此案件）：

DECLARE 
BEGIN 
    FOR FOLDER_ROW IN (SELECT FOLDERID = CASE 
           WHEN FOLDERID = '10' THEN '1' 
           WHEN FOLDERID = '565' THEN '2' 
           WHEN FOLDERID = '11' THEN '3' 
           WHEN FOLDERID = '81' THEN '4' 
           ELSE '0' 
          END, USERID FROM DATA1.FOLDERS WHERE UPPER(OWNER) = 'ADMIN') 
     LOOP      
      INSERT INTO DATA1.FOLDER_USER (FOLDER_ID, CORP_ID) VALUES (FOLDER_ROW.FOLDERID, FOLDER_ROW.CORPID); 
    END LOOP; 
    COMMIT; 
END; 

我收到以下錯誤，當我執行和我堅持爲什麼我得到它。我知道它與選擇內的情況有關：

ORA-06550: line 3, column 39: 
PL/SQL: ORA-00923: FROM keyword not found where expected 
ORA-06550: line 3, column 22: 
PL/SQL: SQL Statement ignored 

Answer 1

SELECT FOLDERID = CASE is wrong。它應該是SELECT CASE ..... END作爲FOLDERID

Answer 2

看起來你只是想

BEGIN 
    FOR FOLDER_ROW IN (SELECT CASE 
           WHEN FOLDERID = '10' THEN '1' 
           WHEN FOLDERID = '565' THEN '2' 
           WHEN FOLDERID = '11' THEN '3' 
           WHEN FOLDERID = '81' THEN '4' 
           ELSE '0' 
          END folder_id, 
          USERID 
         FROM DATA1.FOLDERS 
        WHERE UPPER(OWNER) = 'ADMIN') 
     LOOP      
      INSERT INTO DATA1.FOLDER_USER (FOLDER_ID, CORP_ID) VALUES (FOLDER_ROW.FOLDER_ID, FOLDER_ROW.CORPID); 
    END LOOP; 
    COMMIT; 
END; 

我添加的FOLDER_ID的別名CASE聲明並消除來自CASE

的 FOLDERID =位

Answer 3

你也可以把它改寫爲decode （它是便攜性較差，更難雖然讀）

DECLARE 
BEGIN  
    FOR folder_row IN (SELECT DECODE(folderid,'10', '1','565','2','11', '3','81', '4','0') AS folderid , 
           userid 
         FROM data1.folders 
         WHERE UPPER(owner) = 'ADMIN')  
    LOOP         
     INSERT INTO data1.folder_user (folder_id, corp_id) VALUES (folder_row.folderid, folder_row.corpid);  
    END LOOP;  
    COMMIT; 
END; 

看到：http://download.oracle.com/docs/cd/B28359_01/server.111/b28286/functions042.htm

Answer 4

我不知道你是否已經張貼問題之前簡化您的代碼或沒有，但我想看看擺脫遊標的FOR循環完全，只是使用和INSERT語句子-query。

我認爲CURSOR FOR循環已經被Oracle很好地優化了，所以它可能不會運行得更快，但可能更容易理解。

BEGIN 
    INSERT INTO DATA1.FOLDER_USER (FOLDER_ID, CORP_ID) 
    SELECT 
    CASE 
     WHEN FOLDERID = '10' THEN '1' 
     WHEN FOLDERID = '565' THEN '2' 
     WHEN FOLDERID = '11' THEN '3' 
     WHEN FOLDERID = '81' THEN '4' 
     ELSE '0' 
    END folder_id, 
    USERID 
    FROM DATA1.FOLDERS 
    WHERE UPPER(OWNER) = 'ADMIN'; 

    COMMIT; 
END;