mysql中对于查询结果只显示n条连续行的问题#

在领扣上碰到的一个题目:求满足条件的连续3行结果的显示

X city built a new stadium, each day many people visit it and the stats are saved as these columns: id, date, people；

Please write a query to display the records which have 3 or more consecutive rows and the amount of people more than 100(inclusive).

For example, the table stadium:

+------+------------+-----------+

| id   | date       | people    |

+------+------------+-----------+

| 1    | 2017-01-01 | 10        |

| 2    | 2017-01-02 | 109       |

| 3    | 2017-01-03 | 150       |

| 4    | 2017-01-04 | 99        |

| 5    | 2017-01-05 | 145       |

| 6    | 2017-01-06 | 1455      |

| 7    | 2017-01-07 | 199       |

| 8    | 2017-01-08 | 188       |

+------+------------+-----------+

For the sample data above, the output is:

+------+------------+-----------+

| id   | date       | people    |

+------+------------+-----------+

| 5    | 2017-01-05 | 145       |

| 6    | 2017-01-06 | 1455      |

| 7    | 2017-01-07 | 199       |

| 8    | 2017-01-08 | 188       |

+------+------------+-----------+

1.首先先进行结果集的查询

select id,date,people from stadium where people>=100;

2.给查询的结果集增加一个自增列

SELECT @newid:=@newid+1 AS newid,test.*

FROM(SELECT @newid:=0)r, test WHERE people>100

3.自增列和id的差值相同即连续

SELECT @newid:=@newid+1 AS newid,test.* ,@cha:=id-@newid AS cha

FROM(SELECT @newid:=0)r, test WHERE people>100

4.将相同的差值放在同一张表中，并取出连续数量大于3的

select if(count(id)>=3,count_concat(id),null)e from(

SELECT @newid:=@newid+1 AS newid,test.* ,@cha:=id-@newid AS cha

FROM(SELECT @newid:=0)r, test WHERE people>100)

as d group by cha

5.将上步得到的表和主表取得所需要的

SELECT id,DATE,people FROM test,

(SELECT IF (COUNT(id)>3,GROUP_CONCAT(id),NULL)e

FROM (SELECT @newid:=@newid+1 AS newid,test.* ,@cha:=id-@newid AS cha

FROM(SELECT @newid:=0)r, test WHERE people>100)AS d   GROUP BY cha ) AS f

WHERE f.e IS NOT NULL AND FIND_IN_SET(id,f.e);

听说还可以用存储过程来完成，不过我没尝试，稍后尝试

以上

巴特西

MySQL查询显示连续的结果

mysql中对于查询结果只显示n条连续行的问题#

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巴特西

MySQL查询显示连续的结果

mysql中 对于查询结果只显示n条连续行的问题#

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mysql中对于查询结果只显示n条连续行的问题#