Oracle多行记录合并处理

select t2.weekworkid,t2.nr,T.dd
from t2
left join (
  -- 4筛选结果集
  select weekworkid,max(substr(dd,2))dd
  from(
    -- 3使用sys_connect_by_path生成结果集
    select weekworkid,sys_connect_by_path(dd,‘,‘)dd
    from(
      -- 2创建子节点与父节点
      select weekworkid,dd,weekworkid||rn rchild,weekworkid||(rn-1)rfather
      from(
        -- 1对记录添加序号
        select t1.weekworkid,t1.dd,row_number() 
            over(partition by t1.weekworkid order by t1.dd) rn 
        from t1
        where t1.weekworkid in(
          select weekworkid from t2
        )
      )
    )connect by prior rchild = rfather start with rfather like ‘%0‘
  ) group by weekworkid
)T on t2.weekworkid=T.weekworkid
order by weekworkid