计算特定月份中每天的所有记录

Question

I have a table named 'incidents' in MariaDB with the data below

+-----+----------+---------------------+
| ID  | status   |     created_at      |
+-----+----------+---------------------+
|  1  | open     | 2018-07-03 16:15:24 |
|  2  | open     | 2018-07-03 16:15:24 |
|  3  | open     | 2018-07-05 16:15:24 |
|  4  | open     | 2018-07-08 16:15:24 |
|  5  | closed   | 2018-07-15 16:15:24 |
+-----+----------+---------------------+

I want to count all 'open' status per day in a month with a parameter to choose which month and year to get.

For example my value for month is '07' and year '2018'. It should return:

+-------+------------+
| count |    date    |
+-------+------------+
|   0   | 2018-07-01 |
|   0   | 2018-07-02 |
|   2   | 2018-07-03 |
|   0   | 2018-07-04 |
|   1   | 2018-07-05 |
|   0   | 2018-07-06 |
|   0   | 2018-07-07 |
|   1   | 2018-07-08 |
and so on up to July 31(should also be dynamic depending on month and year)
+-------+------------+

Answer 1

Try below query:

   select thedate,case when status is null then 0 else 1 end as count
     from (Select '2018-07-01' As [TheDate]
         Union All
         Select DateAdd(month, 1, TheDate) From dt Where [TheDate] < '2018-07-31') as dt left join tablename 
    on dt.thedate=tablename.date

Answer 2

Use below code to achieve your result set.

Declare Two variables:

var_from_date = Date of First day of the month. var_daydiff = Number of days of month

         WITH RECURSIVE cte_days (months, days, dates, n) AS
        (
          SELECT DATE(DATE_ADD(var_from_date, INTERVAL 0 DAY)) as dates,
                    0 as n
          UNION ALL
          SELECT DATE(DATE_ADD(var_from_date, INTERVAL n+1 DAY)) as dates, 
                    n + 1 as n 
          FROM cte_days WHERE n <= var_daydiff
        )
        SELECT ch.date, IFNULL(COUNT(t.id), 0) as count
        FROM cte_days ch
        LEFT JOIN table t on ch.dates = t.date
        GROUP BY ch.date;

Answer 3

below way you can generate date according to your requirement i have given where gen_date between '2018-07-01' and '2018-12-31' you have to use your date condition that place and use case when and aggregate function

    select gen_date as date ,sum(case when status='open' then 1 else 0 end) as Cnt from

    (    select * from 
        (select adddate('1970-01-01',t4*10000 + t3*1000 + t2*100 + t1*10 + t0) gen_date from
         (select 0 t0 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0,
         (select 0 t1 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t1,
         (select 0 t2 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t2,
         (select 0 t3 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t3,
         (select 0 t4 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t4) v
        where gen_date between '2018-07-01' and '2018-12-31'
    ) as T1 left join your_table t2 on T1.gen_date= date(t2.created_at)
group by gen_date