Join two table and sum count issue

Question

I have three tables

table 1

c_id    c_name         status    p_id         created_at
1       john            1         79        2016-04-13 10:36:44    
2       smith           1         79        2016-04-13 14:25:57
3       phil            1         76        2016-04-18 18:06:21
4       leo             1         76        2016-04-18 15:51:41
5       craig           1         79        2016-04-20 10:44:17
...

table 2

p_id       p_name                         
75         test1             
76         test2             
77         test3             
78         test4             
79         test5             
...

table 3

id        c_id                         
1         1             
2         1             
3         3             
4         4             
5         4             

I need the result:

period        p_id    p_name   total_count  active_count cance_count no_of_occur          
2016-04-13    79      test5    2            2            0           2
2016-04-18    76      test2    2            2            0           2
2016-04-20    79      test5    1            1            0           1
...

For code that I wrote quert but it gives me wrong count

SELECT 
   DATE(DATE_ADD(created_at, INTERVAL 19800 SECOND)) AS period, table1.p_id, 
   MIN(mdcpev.value) AS product_name,
   COUNT(table1.c_id) AS total_count,
   SUM(status = 1) AS active_count,
   SUM(status = 2) AS cancel_count,
   COUNT(table3.id) AS no_of_occur,
     FROM table1
         INNER JOIN table2 AS mdcpev ON mdcpev.p_id = p_id
         LEFT JOIN table3 AS mdspo ON mdspo.c_id = tabe1.c_id
         GROUP BY DATE(DATE_ADD(created_at, INTERVAL 19800 SECOND)),p_id

---

EDIT

my current query result is

   period        p_id    p_name   total_count  active_count cance_count no_of_occur          
    2016-04-13    79      test5    3            3            0           3
    2016-04-18    76      test2    3            3            0           2
    2016-04-20    79      test5    1            1            0           1

Here I got active_count 3 which is wrong it should be 2 and no_of_occur should be 2 and currently it display 3 Can anyone guide me to the what's wrong in this query ?

Thank you

Answer 1

Tha cause of the difference is the join with table3, since you have 1 and 4 twice in the c_id column and these will duplicate the records.

I would change the counts as follows:

COUNT(distinct table1.c_id) AS total_count,
Count(distinct case when status = 1 then table1.c_id else null end) AS active_count,
Count(distinct case when status = 2 then table1.c_id else null end) AS cancel_count,
COUNT(distinct table3.id) AS no_of_occur,

The distinct within the count ensures that only distinct values are counted. However, you will still have an issue with no_of_occur. If that is based on table3.id, then you will still get 3 for p_id 79 in the 1st record because the 1st record in table1 relates to 2 records in table3 and the second record in table1 relates to a 3rd record in table3. So, I believe your expectations are either incorrect or your no_of_occur calculation should not be tied to table3 at all. But in this case you do not even need table3 in the query. This is sg only you can answer.

Answer 2

SUM(status = 1) AS active_count , this always return true(1) for all condition. So you getting wrong output.

I hope this query will work.Please check.

SELECT
    DATE_FORMAT(table1.created_at,'%Y-%m-%d'),
    table1.p_id,
    table2.p_name,
    COUNT(table1.c_id) AS total_count,
    SUM(CASE WHEN status= 1 THEN 1  ELSE 0 END) AS active_count,
    SUM(CASE WHEN status= 2 THEN 1  ELSE 0 END) AS cancel_count,
    COUNT(table3.id) AS no_of_occur
       FROM table1
       JOIN table2
       on table2.p_id=table1.p_id
       JOIN table3
       ON table3.c_id=table1.c_id
       Group by DATE_FORMAT(table1.created_at,'%Y-%m-%d'),table1.p_id

Answer 3

Try this query, it will work.

    SELECT
        DATE_FORMAT(table1.created_at,'%Y-%m-%d'),
        table1.p_id,
        table2.p_name,
        COUNT(table1.c_id) AS total_count,
        COUNT(CASE WHEN status = 1 THEN table1.c_id ELSE NULL end) AS active_count,
        COUNT(CASE WHEN status = 2 THEN table1.c_id ELSE NULL end) AS cancel_count,
        COUNT(table3.id) AS no_of_occur
           FROM table1
           JOIN table2
           on table2.p_id=table1.p_id
           JOIN table3
           ON table3.c_id=table1.c_id
           Group by DATE_FORMAT(table1.created_at,'%Y-%m-%d'),table1.p_id

Output: I took dumy data as it from question and tried in my system..