SQL查询以获取表中的单词数 [英] SQL Query to get count of words in table

问题描述

我有一个具有这样的架构的表

I have a table which have schema like this

id name

1 jack
2 jack of eden
3 eden of uk
4 m of s

我想执行一个查询，该查询可以给我这样的单词

I want to execute a query which gives me count of words like this

count word
2 jack
2 eden
3 of

这意味着杰克去过这里2次，伊甸园2次，其中曾3次.

this means jack has been here 2 times, eden 2 times and of has been 3 times.

希望您也有问题，也可以尝试，但没有得到正确的查询或解决方法

Hope you got the question, m trying too but not getting the right query or approach to it

thnx

推荐答案

假设您的表名为temp(可能不是-将其更改为表的正确名称)

Assuming your table is named temp (probably not - change it to the right name of your table)

我使用子查询来查找表中的所有单词:

I used a subquery for finding all the words in your table:

select distinct regexp_substr(t.name, '[^ ]+',1,level) word , t.name, t.id
     from temp t
     connect by level <= regexp_count(t.name, ' ') + 1

此查询从所有记录中拆分所有单词.我将其别名为words.
然后，我将它与您的表(在查询中称为temp)连接起来，并计算每条记录中出现的次数.

this query splits all the words from all records. I aliased it words.
Then I joined it with your table (in the query it's called temp) and counted the number of occurences in every record.

select words.word, count(regexp_count(tt.name, words.word))
from(
select distinct regexp_substr(t.name, '[^ ]+',1,level) word , t.name, t.id
 from temp t
 connect by level <= regexp_count(t.name, ' ') + 1) words, temp tt
 where words.id= tt.id
 group by words.word

您还可以添加:

having count(regexp_count(tt.name, words.word)) > 1

---

更新:为了获得更好的性能，我们可以将内部子查询替换为流水线函数的结果:
首先，创建一个架构类型及其表:

---

update: for better performance we can replace the inner subquery with the results of a pipelined function:
first, create a schema type and a table of it:

create or replace type t is object(word varchar2(100), pk number);
/
create or replace type t_tab as table of t;
/

然后创建函数:

create or replace function split_string(del in varchar2) return t_tab
  pipelined is

  word    varchar2(4000);
  str_t   varchar2(4000) ;
  v_del_i number;
  iid     number;

  cursor c is
    select * from temp; -- change  to your table

begin

  for r in c loop
    str_t := r.name;
    iid   := r.id;

    while str_t is not null loop

      v_del_i := instr(str_t, del, 1, 1);

      if v_del_i = 0 then
        word  := str_t;
        str_t := '';
      else
        word  := substr(str_t, 1, v_del_i - 1);
        str_t := substr(str_t, v_del_i + 1);
      end if;

      pipe row(t(word, iid));

    end loop;

  end loop;

  return;
end split_string;

现在查询应如下所示:

select words.word, count(regexp_count(tt.name, words.word))
from(
select word, pk as id from table(split_string(' '))) words, temp tt
 where words.id= tt.id
 group by words.word

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