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kurs:group_by_beispiele [2012/09/25 17:22]
127.0.0.1 external edit
kurs:group_by_beispiele [2020/05/18 11:25] (current)
admin
Line 1: Line 1:
 +<​code>​
 +select ​
 +    department_name,​
 +    count(*) c
 +from employees e join departments d
 +on e.department_id = d.department_id
 +group by 
 +    department_name
 +having count(*) >= 5    ​
 +order by c desc    ​
 +</​code>​
 +
 +
 +<​code>​
 +with ym as (
 +select employee_id,​
 +    --   ​extract(year from hire_date) y,
 +       ​extract(month from hire_date) m
 +       from employees
 +
 +select m, count(employee_id)
 +  from ym 
 +       group by m
 +       order by m
 +</​code> ​      
 +       
 +
 +
 +<​code>​
 +with gehaltklassen as (
 +select salary, case when salary < 7000 then 0
 +            when salary < 12000 then 1
 +            else 2 end gehaltklasse
 +from employees
 +)
 +select gehaltklasse,​ dg, count(dg) from (
 +   ​select gehaltklasse,​ decode(gehaltklasse,​
 +          0, '​wenig',​
 +          1, '​mittel',​
 +          2, '​viel'​) dg
 +     from gehaltklassen )
 +group by gehaltklasse,​ dg 
 +order by gehaltklasse
 +</​code>​
  
 <​code>​ <​code>​
kurs/group_by_beispiele.1348586541.txt.gz ยท Last modified: 2014/09/10 21:22 (external edit)