Oracle動態DESC和ASC按順序排列

Question

排序是動態的，但排序順序是靜態的。

SELECT ... 
Order By CASE WHEN InputParam = 'PRICE' THEN OFFER_PRICE END DESC, 
     CASE WHEN InputParam = 'ENDING SOON' THEN EXPIRY_DATE END DESC, 
     CASE WHEN InputParam = 'DISCOUNT' THEN DISC_PERCENTAGE END DESC, 
     CASE WHEN InputParam = 'SAVING' THEN SAVING END DESC 

現在我需要確保排序順序也是動態的。在上面的查詢中有沒有辦法使排序順序動態化？

Answer 1

如果你也想讓排序順序（ASC/DESC）的動態，你可以做到以下幾點：

SELECT ... 
Order By CASE WHEN InputParam = 'PRICE' THEN l_so * OFFER_PRICE END, 
     CASE WHEN InputParam = 'ENDING SOON' 
       THEN l_so * (SYSDATE - EXPIRY_DATE) END, 
     CASE WHEN InputParam = 'DISCOUNT' THEN l_so * DISC_PERCENTAGE END, 
     CASE WHEN InputParam = 'SAVING' THEN l_so * SAVING END 

與包含1或變量l_so -1取決於其排序順序你想。

Answer 2

這個工作對我來說：

order by 
    case when :dir_param = 'ASC' then 
    case :col_param 
     when 'col_1_identifier' then col_1_name 
     when 'col_2_identifier' then col_2_name 
     ... 
    end 
    end, 
    case when :dir_param = 'DSC' then 
    case :col_param 
     when 'col_1_identifier' then col_1_name 
     when 'col_2_identifier' then col_2_name 
     ... 
    end 
    end desc 

或

order by 
case when :dir_param = 'ASC' and :col_param = 'col_1_identifier' then col_1_name end, 
case when :dir_param = 'DSC' and :col_param = 'col_1_identifier' then col_1_name end desc, 
case when :dir_param = 'ASC' and :col_param = 'col_2_identifier' then col_2_name end, 
case when :dir_param = 'DSC' and :col_param = 'col_2_identifier' then col_2_name end desc 

代替文字，變量名和列名的特定於您的情況。 Oracle似乎對desc sort direction限定符的位置非常挑剔。