Question

i have 3 tables A,B and C.

• table A has column employee_name,id
• table B is the main table and has columns id,os version.
• table c has the columns id,package id and p_version.

I want to query the count of employee_name where the id of table a and c are matched with id of table b(which is the main table).

I should also get the names of employees grouped by the os version they have and also the p_version.

i have tried,

select count(employee_name),os.version,p_version where a.id=b.id and b.id=c.id;

i want the count of employee names to be grouped by os.version and p_version.

Answer 1

I’m not too certain I understand your requirements .. the following is a blind guess.

I’m not too certain how table c should be connected to table b, btw .. somehow the schema doesn’t make alot of sense to me!

select  b.os
     , c.package_version
     , count(a.employee_name)
from B
  join A  on (b.id=a.id)
  join C  on (b.id=c.id)
group by b.os,c.package_version