要求：将125万数据的兑换码，分25列，一列5万数据提取出来

本文介绍了一种使用SQL从大型数据集中批量提取特定列的方法。针对包含125万个兑换码的数据，通过并行处理和decode函数，实现了每列5万个数据的精确提取。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

/*要求：将125万数据的兑换码，分25列，一列5万数据提取出来
*/
select /*+ parallel(cc,4) */ max(decode(rn, 1, exch_code)) col1,
       max(decode(rn, 2, exch_code)) col2,
       max(decode(rn, 3, exch_code)) col3,
       max(decode(rn, 4, exch_code)) col4,
       max(decode(rn, 5, exch_code)) col5,
       max(decode(rn, 6, exch_code)) col6,
       max(decode(rn, 7, exch_code)) col7,
       max(decode(rn, 8, exch_code)) col8,
       max(decode(rn, 9, exch_code)) col9,
       max(decode(rn, 10, exch_code)) col10,
       max(decode(rn, 11, exch_code)) col11,
       max(decode(rn, 12, exch_code)) col12,
       max(decode(rn, 13, exch_code)) col13,
       max(decode(rn, 14, exch_code)) col14,
       max(decode(rn, 15, exch_code)) col15,
       max(decode(rn, 16, exch_code)) col16,
       max(decode(rn, 17, exch_code)) col17,
       max(decode(rn, 18, exch_code)) col18,
       max(decode(rn, 19, exch_code)) col19,
       max(decode(rn, 20, exch_code)) col20,
       max(decode(rn, 21, exch_code)) col21,
       max(decode(rn, 22, exch_code)) col22,
       max(decode(rn, 23, exch_code)) col23,
       max(decode(rn, 24, exch_code)) col24,
       max(decode(rn, 25, exch_code)) col25
  from (select seq,
               row_number() over(partition by seq order by 1) rn,
               exch_code
          from (select mod(rownum, 50000) + 1 seq, exch_code
                  from sif_ticket_exchange_code
                 where ticket_cd = '000000000001434')) cc
 group by seq;