Oracle 合并表中的相同数据：

--合并关键字的命中率到一个字段
update table b  set b.times=(
                    select c.cout from (
                            select a.keyword,count(*) as cout,min(a.rowid) as temprowid from  table  a group by  a.keyword
                            ) c
                            where b.rowid=c.temprowid)
            
                   where b.rowid in (select c.temprowid from (select a.keyword,count(*) as cout,min(a.rowid) as temprowid from  table  a group by  a.keyword) c)
                  
                  
--简化之后（java代码中用下面来做。提高性能）
update Table b  set b.times=(
                   
                            select count(*) from Table a group by  a.keyword
                       
                            where a.rowid=?)
            
                   where b.rowid =?

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