数据库行合并

month  callnum

 1   12221

 2   3232323

 3   12224

 1   12224

 1   12223

 2   22233

 2   12221

3    5555

3    58877

3    5555

1    12221

2    12224

3    12221

2    22233

把相同的月份的不同行合并 结果是

month     callnum

1     12221/12221/12223/12224

2     3232323/22233/12224/12221/22233

3     12224/12221/5555/58877/5555

SQL语句如下：

 SELECT MONTH, REPLACE(WMSYS.WM_CONCAT(CALLNUM), ',' , '/') AS "NEW_NUM"

  FROM DETAIL T GROUP BY MONTH;

选出每个月都来电的号码并计算每个月该号码的来电次数

select t.callnum, count( distinct t.month) from DETAIL t  group by callnum

having  count (distinct t.month) =(select(count (distinct t.month)) from  DETAIL t)