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kurs:correlated_subquery [2014/09/10 21:22]
127.0.0.1 external edit
kurs:correlated_subquery [2022/03/15 10:39] (current)
admin
Line 1: Line 1:
 +<​code>​
 +with cte_multiple_last_names as (
 +select last_name,
 +       ​count(*) c
 +  from hr.employees
 +  group by last_name
 +  having count(*) > 1
 +  order by c desc
 +)
 +select employee_id,​
 +   ​first_name,​
 +   ​last_name
 +from hr.employees where last_name ​
 +  in (select last_name from cte_multiple_last_names)
 +
 +
 +select ​
 +  emp.first_name,​
 +  emp.last_name
 +from 
 +  hr.employees emp
 +where 
 +  (select count(last_name) from hr.employees emp_sub where emp_sub.last_name = emp.last_name) > 1
 +
 <​code>​ <​code>​
 select first_name, last_name, e.employee_id,​ c from employees e, select first_name, last_name, e.employee_id,​ c from employees e,
Line 45: Line 69:
         and  outer.fhz_name = inner.fhz_name         and  outer.fhz_name = inner.fhz_name
        )) > 1        )) > 1
 +</​code>​
 +
 +<​code>​
 +with emp_per_country as (
 +SELECT dep.department_id, ​
 +    department_name,​
 +    cou.country_id,​
 +    country_name, ​
 +    COUNT(employee_id) c
 +FROM hr.employees emp
 +JOIN hr.departments dep
 +ON emp.department_id = dep.department_id
 +JOIN hr.locations loc
 +ON loc.location_id = dep.location_id
 +JOIN hr.countries cou
 +ON cou.country_id = loc.country_id
 +GROUP BY dep.department_id,​ department_name,​ cou.country_id,​ country_name
 +ORDER BY COUNT(employee_id) DESC
 +)
 +select country_name,​ department_name,​ c from emp_per_country o
 +where c = (select max(c) from emp_per_country where country_id = o.country_id)
 </​code>​ </​code>​
kurs/correlated_subquery.1410376975.txt.gz ยท Last modified: 2014/09/10 21:22 by 127.0.0.1