ORACLE SQL |爲了在Oracle表修改數據BY

Question

結構如下：

FILE_NAME 
----------- 
12345_l.tif 
12345_m.tif 
12345_r.tif 
12345_x.tif 
12345_y.tif 

需要以下結果：

First *_m* 
Then *_l* 
Then *_r* 
Then * (everything else) 

與嘗試：

SELECT FILE_NAME FROM TABLE 
WHERE FILE_NAME LIKE '12345%' 
ORDER BY regexp_replace(FILE_NAME, '_m', '_1'), 
     regexp_replace(FILE_NAME, '_l', '_2'), 
     regexp_replace(FILE_NAME, '_r', '_3') 

但是這給了我一個錯誤的結果。

任何人只要有一個提示？

TIA馬特

Answer 1

更改ORDER BY通過一個數字來訂購吧：

ORDER BY regexp_replace(FILE_NAME, '_m', 1), 
      regexp_replace(FILE_NAME, '_l', 2), 
      regexp_replace(FILE_NAME, '_r', 3); 

例如

WITH t 
    AS (SELECT '12345_l.tif' AS file_name FROM dual 
     UNION 
     SELECT '12345_m.tif' FROM dual 
     UNION 
     SELECT '12345_r.tif' FROM dual 
     UNION 
     SELECT '12345_x.tif' FROM dual 
     UNION 
     SELECT '12345_y.tif' FROM dual) 
SELECT file_name 
    FROM t 
ORDER BY regexp_replace(FILE_NAME, '_m', 1), 
      regexp_replace(FILE_NAME, '_l', 2), 
      regexp_replace(FILE_NAME, '_r', 3); 

給出：

============== 
12345_m.tif 
12345_l.tif 
12345_r.tif 
12345_x.tif 
12345_y.tif 

希望它可以幫助...

另外，您可以使用：

ORDER BY (CASE SUBSTR(file_name, INSTR(file_name, '_')+1, 1) 
      WHEN 'm' THEN 1 
      WHEN 'l' THEN 2 
      WHEN 'r' THEN 3 
      ELSE 4 
      END) ASC; 

例如爲：

WITH t 
    AS (SELECT '12345_l.tif' AS file_name FROM dual 
     UNION 
     SELECT '12345_y.tif' FROM dual 
     UNION 
     SELECT '12345_r.tif' FROM dual 
     UNION 
     SELECT '12345_x.tif' FROM dual 
     UNION 
     SELECT '12345_m.tif' FROM dual) 
SELECT file_name 
    FROM t 
ORDER BY (CASE SUBSTR(file_name, INSTR(file_name, '_')+1, 1) 
      WHEN 'm' THEN 1 
      WHEN 'l' THEN 2 
      WHEN 'r' THEN 3 
      ELSE 4 
      END) ASC; 

給出：

12345_m.tif 
12345_l.tif 
12345_r.tif 
12345_x.tif 
12345_y.tif