在oracle中使用存储过程进行分页和排序

Question

我创建了一个用于分页的存储过程。现在我正在寻找列排序。

我的工作分页存储过程：

PROCEDURE paging (PageSize     IN     INT,
                  PageIndex    IN     INT,
                  SortColumn   IN     VARCHAR,
                  PageData        OUT Page) AS
    FirstIndex   INT;
    LastIndex    INT;
    SortCol      VARCHAR;
BEGIN
    LastIndex := PageSize * (PageIndex + 1);
    FirstIndex := LastIndex - PageSize + 1;
    SortCol := SortColumn;

    OPEN PageData FOR
        SELECT *
          FROM (SELECT a.*, ROWNUM AS rnum
                  FROM (  SELECT *
                            FROM table_name
                        ORDER BY SortCol) a
                 WHERE ROWNUM <= LastIndex)
         WHERE rnum >= FirstIndex;
END paging;
/

Answer 1

我建议您使用一个很棒的特性，称为Dynamic SQL (Oracle Docs)。

我还修改了您的SQL查询，使用了ROW_NUMBER()而不是rownum。与后者相比，它是一种更健壮的对输出行进行排序和编号的方法。

我还从PL/SQL中删除了一些我认为不需要的变量：

PROCEDURE paging (PageSize     IN     INT,
                  PageIndex    IN     INT,
                  SortColumn   IN     VARCHAR2, -- Assuming this always contains
                                                -- the ordering column name
                  PageData        OUT Page) AS
    FirstIndex   INT;
    LastIndex    INT;
    v_sql        VARCHAR2(4000);
BEGIN
    LastIndex := PageSize * (PageIndex + 1);
    FirstIndex := LastIndex - PageSize + 1;

    v_sql :=  'SELECT *'
            ||'  FROM (SELECT a.*,'
            ||'              ROW_NUMBER() '
            ||'                OVER (ORDER BY ' || SortColumn || ') AS rnum'
            ||'          FROM table_name a)'
            ||' WHERE rnum BETWEEN FirstIndex AND LastIndex';

    OPEN PageData FOR v_sql;

END paging;
/

Answer 2

仅此SP就可以完成Oracle中的所有三件事，Paging, Sorting and Filtering of records。

create or replace procedure GetResults 
(
 p_userId In Number,
 p_dueDateFrom In Date,
 p_dueDateTo in Date,
 p_durationMax in Number,
 p_durationMin in Number,
 p_sortColumn In Varchar2,
 p_sortOrder In Varchar2,
 p_pageSize In Number,
 p_pageIndex in number,
 cv_1 OUT SYS_REFCURSOR
)
as 
v_FirstIndex   NUMBER;
v_LastIndex    NUMBER;
begin
-- Paging
  v_LastIndex := p_pageSize * (p_pageIndex + 1);
  v_FirstIndex := v_LastIndex - p_pageSize + 1;

 OPEN cv_1 FOR 

  SELECT * FROM (SELECT a.*, ROWNUM AS rnum
              FROM (Select * From Newjob nj Where nj.userId = p_userId  
               -- Filtering
             And ((p_dueDateFrom IS NULL AND p_dueDateTo Is NULL) OR 
                  (nj.Due_Date >= p_dueDateFrom and nj.Due_Date <= p_dueDateTo)
                 )
             And ((p_durationMax IS NULL AND p_durationMin Is NULL) OR 
                  (nj.Duration >= p_durationMax and nj.Duration <= p_durationMin)
                 )   
             -- Sorting     
            order by   
            Case when p_sortOrder = 'Ascending' And p_sortColumn = 'DUE_DATE' then  nj.Due_Date End,
            Case When p_sortOrder = 'Ascending' And p_sortColumn = 'DURATION' then nj.DURATION end,     
            Case when p_sortOrder = 'Descending' And p_sortColumn = 'DUE_DATE' then  nj.Due_Date End desc,
            Case When p_sortOrder = 'Descending' And p_sortColumn = 'DURATION' then nj.DURATION end desc)a
   WHERE ROWNUM <= v_LastIndex)    
   WHERE rnum >= v_FirstIndex;
end;