Lista de cursos Entrar

Informações

Autores Quentin Cappart
Prazo de entrega Sem prazo
Limite de submissão No limitation

Entrar

Entrar

Compréhension des mots-clefs (fenêtrage)

Parmi les propositions suivantes, trouvez celle donnant une description correcte des mots-clefs (ou requêtes) suivants.

Questão 1: 
select name, salary, sum(salary) over () as total_salary
from instructor;
Questão 2: 
select name, dept_name, salary, sum(salary) over (partition by dept_name) as total_salary
from instructor;
Questão 3:

Que représente l'attribut new_attribute dans cette requête ?

select name, salary, dept_name, sum(salary) over (order by salary) as new_attribute
from instructor;
Questão 4:

Que représente l'attribut new_attribute dans cette requête ?

select name, salary, avg(salary) over (order by salary desc rows between 1 preceding and 2 following) AS new_attribute
from instructor;
Questão 5: 
select name, salary, dept_name, sum(salary) over (partition by dept_name
                                                  order by salary asc
                                                  rows between unbounded preceding and current row)
                                                  AS new_attribute
from instructor
order by dept_name, salary;