oracle：带案例的过程

Question

为什么这个程序不起作用？ 我试图通过游标获取表的行：AF_EMPLOYEE，这将使用 ASC/DESC 排序（根据情况）。

Create or Replace Procedure return_rows_EMPLOYEE (in_order in number, 
in_sorting in VARCHAR2, in_job in VARCHAR2, out_cursor OUT SYS_REFCURSOR) As
Begin
  OPEN out_cursor for
  select * from AF_EMPLOYEE
  WHERE EMPL_JOB_TITLE = in_job
  ORDER BY in_sorting
  CASE in_order
  WHEN 1 THEN   ASC
  ELSE  DESC
  END
End; 

Answer 1

如果排序列是数字，可以用case取反，但这不是好代码！

CREATE OR REPLACE PROCEDURE return_rows_EMPLOYEE (in_order in number, 
in_sorting in VARCHAR2, in_job in VARCHAR2, out_cursor OUT SYS_REFCURSOR) As
Begin
  OPEN out_cursor for
  select * from AF_EMPLOYEE
  WHERE EMPL_JOB_TITLE = in_job
  ORDER BY 
    CASE in_sorting WHEN 'ASC'  THEN  sort_column 
                    WHEN 'DESC' THEN -sort_column 
     END;
END; 
/

Answer 2

Create or Replace Procedure return_rows_EMPLOYEE (in_order in number, 
in_sorting in VARCHAR2, in_job in VARCHAR2, out_cursor OUT SYS_REFCURSOR) As
Begin
  if in_order = 1 THEN
     OPEN out_cursor for
     select * from AF_EMPLOYEE
     WHERE EMPL_JOB_TITLE = in_job
     ORDER BY in_sorting ASC
  else
     OPEN out_cursor for
     select * from AF_EMPLOYEE
     WHERE EMPL_JOB_TITLE = in_job
     ORDER BY in_sorting DESC
  end if;
End; 

更新 试试这个：

Create or Replace Procedure return_rows_EMPLOYEE (in_order in number, 
in_sorting in VARCHAR2, in_job in VARCHAR2, out_cursor OUT SYS_REFCURSOR) As
Begin
  OPEN out_cursor for
  select * from AF_EMPLOYEE
  WHERE EMPL_JOB_TITLE = in_job
  ORDER BY 
  case when in_order = 1 then
      in_sorting 
  end,
  case when in_order <> 1 then
      in_sorting
  end desc;
End;