HQL function--Whack-a-mole game and WordCount case analysis and implementation

1. Whac-a-mole

uid,hit,m
1,1,0
1,2,1
1,3,1
1,4,1
1,5,0
1,6,0
1,7,1
2,1,1
2,2,1
2,3,1
2,4,1
2,5,1
3,1,1
3,2,1
3,3,1
3,4,0
3,5,0
3,6,1
3,7,0
3,8,1

create table tb_ds(
      uid int, -- user name
      hit int, -- the number of whack-a-mole
      m int -- whether it hit 1, hit 0, missed
)
row format delimited fields terminated by ',' ;
load data local inpath '/ root/ds.txt' into table tb_ds;

select  * from tb_ds;

 case analysis

Query the user's maximum number of consecutive hits

--查询命中的的记录
select *
from tb_ds
where m = 1;

-- 用户分组 记录编号
select uid, hit, row_number() over (partition by uid order by hit) as rn
from tb_ds
where m = 1;

-- hit-rn 
with t1 as (select uid, hit, row_number() over (partition by uid order by hit) as rn from tb_ds where m = 1)
select *, (hit - rn) as sub
from t1

-- 分组得到每个用户的连续击中
with t1 as (select uid, hit, row_number() over (partition by uid order by hit) as rn from tb_ds where m = 1),
     t2 as (select *, (hit - rn) as sub from t1)
select uid, count(*) as hit_count
from t2
group by uid, sub

-- 用户分组得到每个用户最大次数
with t1 as (select uid, hit, row_number() over (partition by uid order by hit) as rn from tb_ds where m = 1),
    t2 as (select *, (hit-rn) as sub from t1 ),
    t3 as (select uid, count(*) as hit_count from t2 group by uid, sub )
select uid, max(hit_count) as hit_count
from t3
group by uid;

2.WordCount

 1. Create table data

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2.Analysis 

 

 

create table t_wc(
    line string
)row format delimited lines terminated by "\n";

load data local inpath '/root/word.txt' overwrite into table t_wc;
select * from t_wc;

-- 使用正则表达式去掉特殊符号 将 除了单词字符 及 ' 和 空格的 所有字符替换成空串
select regexp_replace(line, '[^a-zA-Z_0-9\'\\s]', "") as word_line
from t_wc;
-- 使用split进行切割 将一行数据切割为一个数组
select split(regexp_replace(line, '[^a-zA-Z_0-9\'\\s]', ""), "\\s+")
from t_wc;
-- 使用expload函数进行炸裂
select explode(split(regexp_replace(line, '[^a-zA-Z_0-9\'\\s]', ""), "\\s+")) as word
from t_wc;
-- 分组得到每个单词的次数
with t1 as (select explode(split(regexp_replace(line, '[^a-zA-Z_0-9\'\\s]', ""), "\\s+")) as word from t_wc)
select word, count(1) as word_count
from t1
group by word;