如何解决MySql：计算单词在列中出现的次数
| 例如，如果我在这样的列中有数据data
I love book
I love apple
I love book
I hate apple
I hate apple
I = 5
love = 3
hate = 2
book = 2
apple = 3
解决方法
这是仅使用查询的解决方案：
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
create table tbl(str varchar(100) );
insert into tbl values(\'data\');
insert into tbl values(\'I love book\');
insert into tbl values(\'I love apple\');
insert into tbl values(\'I love book\');
insert into tbl values(\'I hate apple\');
insert into tbl values(\'I hate apple\');
SELECT DISTINCT str AS Word,COUNT(str) AS Frequency FROM tbl GROUP BY str;
DELIMITER $$
CREATE FUNCTION `getCount`(myStr VARCHAR(1000),myword VARCHAR(100))
RETURNS INT
BEGIN
DECLARE cnt INT DEFAULT 0;
DECLARE result INT DEFAULT 1;
WHILE (result > 0) DO
SET result = INSTR(myStr,myword);
IF(result > 0) THEN
SET cnt = cnt + 1;
SET myStr = SUBSTRING(myStr,result + LENGTH(myword));
END IF;
END WHILE;
RETURN cnt;
END$$
DELIMITER ;
drop table if exists mytable;
create table mytable (
id int not null auto_increment primary key,mytext varchar(1000)
) engine = myisam;
insert into mytable (mytext)
values (\'I love book,but book sucks!What do you,think about it? me too\'),(\'I love apple! it rulez.,No,it sucks a lot!!!\'),(\'I love book\'),(\'I hate apple!!! Me too.,!\'),(\'I hate apple\');
drop table if exists mywords;
create table mywords (
id int not null auto_increment primary key,word varchar(50)
) engine = myisam;
delimiter //
drop procedure if exists split_string //
create procedure split_string (
in input text,in `delimiter` varchar(10)
)
sql security invoker
begin
declare cur_position int default 1 ;
declare remainder text;
declare cur_string varchar(1000);
declare delimiter_length tinyint unsigned;
drop temporary table if exists SplitValues;
create temporary table SplitValues (
value varchar(1000) not null
) engine=myisam;
set remainder = input;
set delimiter_length = char_length(delimiter);
while char_length(remainder) > 0 and cur_position > 0 do
set cur_position = instr(remainder,`delimiter`);
if cur_position = 0 then
set cur_string = remainder;
else
set cur_string = left(remainder,cur_position - 1);
end if;
if trim(cur_string) != \'\' then
insert into SplitValues values (cur_string);
end if;
set remainder = substring(remainder,cur_position + delimiter_length);
end while;
end //
delimiter ;
delimiter //
drop procedure if exists single_words//
create procedure single_words()
begin
declare finish int default 0;
declare str varchar(200);
declare cur_table cursor for select replace(replace(replace(replace(mytext,\' \'),\',\' \') from mytable;
declare continue handler for not found set finish = 1;
truncate table mywords;
open cur_table;
my_loop:loop
fetch cur_table into str;
if finish = 1 then
leave my_loop;
end if;
call split_string(str,\' \');
insert into mywords (word) select * from splitvalues;
end loop;
close cur_table;
end;//
delimiter ;
call single_words();
select word,count(*) as word_count
from mywords
group by word;
+-------+------------+
| word | word_count |
+-------+------------+
| a | 1 |
| about | 1 |
| apple | 3 |
| book | 3 |
| but | 1 |
| do | 1 |
| hate | 2 |
| I | 5 |
| it | 3 |
| lot | 1 |
| love | 3 |
| me | 2 |
| No | 1 |
| rulez | 1 |
| sucks | 2 |
| think | 1 |
| too | 2 |
| What | 1 |
| you | 1 |
+-------+------------+
19 rows in set (0.00 sec)
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