简单搞一下 Oracle 存储过程动态SQL之获取查询分页！

Oracle 动态SQL之查询分页

原理：动态组装SQL，利用oracle rownum 虚列嵌套查询实现！

procedure proc_goods_search_list( p_type number,
                                   p_keywords varchar2,
                                   p_index    number,
                                   p_size     number,
                                   p_order    number,
                                   p_cursor   out p_cursor) is
    v_start NUMBER(10);
    v_end   NUMBER(10);
    v_sql   varchar2(4000);
  begin
    v_start := (p_index -1) * p_size +1;
    v_end   := p_index * p_size;
  
    v_sql :=' select  a.serialno as goodsId,
                       a.goods_name as goodsName,
                       a.sale_price as price,
                       a.sale_amount as saleAmount,
                       a.comment_count as commentCount,
                       a.goods_images as goodsImage,
                       a.promotion_type as promotionType,
                       nvl(a.promotion_price,0) as promotionPrice,
                       a.publish_time as createTime,
                       a.promotion_start_time as promotionStartTime,
                       a.promotion_end_time as promotionEndTime
                  from lt_goods a
                     where a.status = 2';
  
    if p_type isnotnulland p_type <>0then
      v_sql := v_sql ||' and a.goods_type ='|| p_type;
    endif;
    if p_keywords isnotnullthen
      v_sql := v_sql ||' and a.goods_name like ''%'|| p_keywords ||'%''';
    endif;
  
    if p_order isnotnulland p_order =0then
      -- 全部商品
      v_sql := v_sql ||' order by goodsId desc ';
    endif;
  
    if p_order isnotnulland p_order =1then
      -- 时间
      v_sql := v_sql ||' order by createTime desc ';
    endif;
  
    if p_order isnotnulland p_order =2then
      -- 销量
      v_sql := v_sql ||' order by saleAmount desc';
    endif;
  
    if p_order isnotnulland p_order =3then
      -- 价格
      v_sql := v_sql ||' order by price desc';
    endif;
    v_sql :='select m.*,rownum as id from ('|| v_sql ||')m ';
    v_sql :='select * from ('|| v_sql ||') where id <= '||
             to_char(v_end);
    v_sql :='select * from ('|| v_sql ||') where id >= '||
             to_char(v_start);
    /×dbms_output.put_line(v_sql);×/
    open p_cursor for v_sql;
  
  end proc_goods_search_list;

查询分页存储过程定义

procedure proc_goods_search_list(  p_type     number,
                                   p_keywords varchar2,
                                   p_index    number,
                                   p_size     number,
                                   p_order    number,
                                   p_cursor   out p_cursor) 

 参数说明：

  传入参数： 商品类型        p_type,

                 查询关键字     p_keywords,

                 分页索引        p_index,

                 页包含数量     p_size,

                 排序标识        p_order,

  传出参数： 查询游标       p_cursor

动态SQL局部变量及分页算法

分页原理，通过利用rownum oracle 虚列标识，通过两层嵌套查询实现

 v_start NUMBER(10);
 v_end   NUMBER(10);
 v_sql   varchar2(4000);

 

 v_start := (p_index -1) * p_size +1;
 v_end   := p_index * p_size;

v_sql :='select m.*,rownum as id from ('|| v_sql ||')m ';
v_sql :='select * from ('|| v_sql ||') where id <= '||
             to_char(v_end);
v_sql :='select * from ('|| v_sql ||') where id >= '||
             to_char(v_start);

调试组装SQL

dbms_output.put_line(v_sql);

动态执行并输出查询列表

open p_cursor for v_sql;