MySql查询多条记录

Question

我有以下关于 tf/idf 测量的查询。我的目标是获得每个日期的前 10 名，如 20160401 的前 10 名，20160402 的前 10 名 etc.But 根据我的查询，我每个 date.As 有超过 10 个，它可以看到我无法订购，应该只有一个 1 ，一个 2 一个 3 ，我的意思是每个日期最多 10 个。

date     word rowNumber

20160401 word     1
20160401 word     2 
..
20160401 word     10 

-------------------
20160402 word     1
20160402 word     2 
..
20160402 word     10

以下是我对 tf idf 测量的查询。在 newsdetails table 中，我有像

这样的列和值

   date        word     wordCount
 20160401    yürürlük      1
 20160401    mülteci       1
 20160401    anlaşma       2
 20160401    pazartesi     1
 20160401    itibaren      1
 20160401    uygula        2

-------------------

      SELECT t.newsCreatedTime,t.word,t.tf_idf as tweetRatio ,rn
       FROM (
       select w.newsCreatedTime,w.word,w.wordCount,t1.topic_sum,w.wordCount/t1.topic_sum as tf, 
             t2.idf,(w.wordCount/t1.topic_sum)*(t2.idf) as tf_idf,
          (@rn := if(@t = w.newsCreatedTime, @rn + 1,
                     if(@t := w.newsCreatedTime, 1, 1)
                    )
          ) as rn
       FROM newsdetails  w JOIN
       ( select newsCreatedTime, sum(wordCount) as topic_sum 
        from newsdetails where trim(word)<>'limit' and length(trim(word))>3 and  newsCreatedTime>=20160401
        group by newsCreatedTime 
       ) t1
        on w.newsCreatedTime=t1.newsCreatedTime  and trim(w.word)<>'limit' and length(trim(w.word))>3 and  w.newsCreatedTime>=20160401
        join (
          select w.word, log10(t_cnts.cnts/count(*)) as idf 
          from newsdetails w,
          (select count(distinct newsCreatedTime) as cnts from newsdetails where trim(word)<>'limit' and length(trim(word))>3 and  newsCreatedTime>=20160401) t_cnts
          group by w.word 
          ) t2 
         on w.word=t2.word CROSS JOIN
        (SELECT @t := '', @rn := 0) params 
        ORDER BY tf_idf desc 
       ) t
       WHERE rn <=10

输出是：

  Date        word            ratio           rowNumber

20160401    kadın        -0.0005375613007471833      1
20160401    beyaz        -0.00006167450024777626     1
20160401    alışveriş    -0.000015563777946653284    1
20160401    ösym          0                          1
20160401    yürürlük      0.00004586823255826781     1
20160401    haber        -0.0003304889014365445      2
20160401    taraf        -0.00019041987363584725     2
20160401    merkezi      -0.00013800691483414033     2
20160401    mülteci      -0.000056636107108483694    2
20160401    perde         0.00004941253963307586     2
20160401    sınav        -0.00017806007150496475     3

但我只想获得每个日期的前 10 个单词及其比率。

Answer 1

类似的东西可以在 SQL 服务器中运行 - 可能需要调整 MySQL

的语法

select * from(
select *, row_number() over(partition by date order by ratio) rownum from (SELECT t.newsCreatedTime,t.word,t.tf_idf as tweetRatio ,rn
       FROM (
       select w.newsCreatedTime,w.word,w.wordCount,t1.topic_sum,w.wordCount/t1.topic_sum as tf, 
             t2.idf,(w.wordCount/t1.topic_sum)*(t2.idf) as tf_idf,
          (@rn := if(@t = w.newsCreatedTime, @rn + 1,
                     if(@t := w.newsCreatedTime, 1, 1)
                    )
          ) as rn
       FROM newsdetails  w JOIN
       ( select newsCreatedTime, sum(wordCount) as topic_sum 
        from newsdetails where trim(word)<>'limit' and length(trim(word))>3 and  newsCreatedTime>=20160401
        group by newsCreatedTime 
       ) t1
        on w.newsCreatedTime=t1.newsCreatedTime  and trim(w.word)<>'limit' and length(trim(w.word))>3 and  w.newsCreatedTime>=20160401
        join (
          select w.word, log10(t_cnts.cnts/count(*)) as idf 
          from newsdetails w,
          (select count(distinct newsCreatedTime) as cnts from newsdetails where trim(word)<>'limit' and length(trim(word))>3 and  newsCreatedTime>=20160401) t_cnts
          group by w.word 
          ) t2 
         on w.word=t2.word CROSS JOIN
        (SELECT @t := '', @rn := 0) params 
        ORDER BY tf_idf desc 
       ) t
       WHERE rn <=10 )a)b where rownum<=10

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