mysql - 计算表列中的单词出现次数

Question

我有一个带有 varchar(255) 字段的表。我想(通过查询、函数或 SP)从该表中的一组行中获取每个单词的出现次数。

如果有 2 行包含这些字段:

"I like to eat bananas""I don't like to eat like a monkey"

我想得到

    word | count()    ---------------    like  3    eat   2    to    2    i     2    a     1

有什么想法吗？我正在使用 MySQL 5.2。

Answer 1

@Elad Meidar，我喜欢你的问题，我找到了解决方案:

SELECT SUM(total_count) as total, value
FROM (

SELECT count(*) AS total_count, REPLACE(REPLACE(REPLACE(x.value,'?',''),'.',''),'!','') as value
FROM (
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX(t.sentence, ' ', n.n), ' ', -1) value
  FROM table_name t CROSS JOIN 
(
   SELECT a.N + b.N * 10 + 1 n
     FROM 
    (SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) a
   ,(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) b
    ORDER BY n
) n
 WHERE n.n <= 1 + (LENGTH(t.sentence) - LENGTH(REPLACE(t.sentence, ' ', '')))
 ORDER BY value

) AS x
GROUP BY x.value

) AS y
GROUP BY value

这是完整的工作 fiddle :http://sqlfiddle.com/#!2/17481a/1

首先，我们执行查询以提取所有单词，如 here 所述@peterm(如果你想自定义处理的单词总数，请按照他的说明进行操作)。然后我们将其转换为子查询，然后我们COUNT 和GROUP BY 每个单词的值，然后在此之上进行另一个查询以GROUP BY 未对可能存在伴随符号的词进行分组。即:你好=你好!用 REPLACE