如何创建SQL查询

Question

I have data(result / output) in a table like this:

Project code  project name    associates                   time efforts in days
1             Analytics       amol,manisha,sayali,pooja    (21+17+20+17)=57

I need to calculate the time efforts in days. I have done it for February and I have added each persons days he has worked in that month. I mean I have all days minus absentee of any day of all associates.

So, I need to do this by SQL queries.

I have one table which contains all the associates present with dates.

Like this:

UID username date

So can any one give me a suggestion how I could do this?

Answer 1

It will be a better design to have a separate table to store projectid, team member id and his/her efforts in days. so that you can write a simple join query to achieve what you want.

Answer 2

Here is what I would do. Change you tables so you have:

projects

project_code  project_name
1             Analytics   

users

UID username date
1   amol
2   manisha
3   sayali

projects_users

project_code  uid    effort
1             1      21
1             2      17
1             3      20

Now you can query the result you asked for like this:

SELECT 
  p.project_code,
  p.project_name, 
  GROUP_CONCAT(DISTINCT u.username SEPARATOR ', ') AS associates,
  SUM(pu.effort) effort 
JOIN users AS u
JOIN projects_users AS pu
FROM projects p
GROUP BY project_code