Calculate the number of jobs reviewed per hour per day for November 2020?

Question

This question is really confusing me. They didn't provide enough details of it. Whatever they have provided I have written below.

• job_id: unique identifier of jobs
• actor_id: unique identifier of actor
• event: decision/skip/transfer
• language: language of the content
• time_spent: time spent to review the job in seconds
• org: organization of the actor
• ds: date in the yyyy/mm/dd format. It is stored in the form of text and we use presto to run. no need for date function

CREATE TABLE job_data
(
    ds DATE,
    job_id INT NOT NULL,
    actor_id INT NOT NULL,
    event VARCHAR(15) NOT NULL,
    language VARCHAR(15) NOT NULL,
    time_spent INT NOT NULL,
    org CHAR(2)
);

INSERT INTO job_data (ds, job_id, actor_id, event, language, time_spent, org)
VALUES ('2020-11-30', 21, 1001, 'skip', 'English', 15, 'A'),
    ('2020-11-30', 22, 1006, 'transfer', 'Arabic', 25, 'B'),
    ('2020-11-29', 23, 1003, 'decision', 'Persian', 20, 'C'),
    ('2020-11-28', 23, 1005,'transfer', 'Persian', 22, 'D'),
    ('2020-11-28', 25, 1002, 'decision', 'Hindi', 11, 'B'),
    ('2020-11-27', 11, 1007, 'decision', 'French', 104, 'D'),
    ('2020-11-26', 23, 1004, 'skip', 'Persian', 56, 'A'),
    ('2020-11-25', 20, 1003, 'transfer', 'Italian', 45, 'C');

Below is the data. Points to be considered: What does the event mean? What to consider for reviewing?

And here's the query I've tried:

SELECT ds, COUNT(*)/24 AS no_of_job 
  FROM job_data 
   WHERE ds BETWEEN '2020-11-01' AND '2020-11-30' 
GROUP BY ds;

Answer 1

Check below approach if it is what you are looking for.

select ds,count(job_id) as jobs_per_day, sum(time_spent)/3600 as hours_spent 
from job_data  
where ds >='2020-11-01'  and ds <='2020-11-30'  
group by ds ;

Demo MySQL 5.6 : https://www.db-fiddle.com/f/7yUJcuMJPncBBnrExKbzYz/26

Demo MySQL 8.0.26 : https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=83e89a2ad2a7e73b7ca990ac36ae4df0

The difference between the demos as @FaNo_FN pointed out in the comments is: in MySQL 8.0.26 version it will provide an error if date 2020-11-31 it is used, because there is no 31 Novembre .

Use and condition instead of between , it performs faster.

You need to sum the time_spent for the day.

Answer 2

But they've asked for Calculate the

• number of jobs reviewed per hour per day

for November 2020?

POV: Didn't it means the job review count/hour/day?

You are calculating the (total time spent in sec) per hour per day.