SQL FSR

Dans quels types de jointures l’ordre des tables a-t-il de l’importance ?

• INNER JOIN

• LEFT JOIN

• RIGHT JOIN

• FULL JOIN

• Dans aucune

L’opérateur SELECT fonctionne selon l’axe _______ tandis que l’opérateur PROJECT fonctionne selon l’axe _______.

• • Ligne, Colonne

• Colonne, Ligne

• Ligne, Ligne

• Colonne, Colonne

Pour pouvoir effectuer une opération d’union entre deux relations, celles-ci doivent :

• Avoir le même nombre de colonnes et des types compatibles

• Avoir exactement les mêmes noms de colonnes

• Contenir des données sans doublons

• • Être créées par le même utilisateur

What does "SQL" stand for?

In what order does SQL process the instructions?

• FROM - SELECT - WHERE - ORDER BY

• WHERE - FROM - SELECT - ORDER BY

• SELECT - FROM - WHERE - ORDER BY

• SELECT - FROM - ORDER By - WHERE

A primary key can be NULL in the table? TRUE or FALSE

• TRUE

• FALSE

Q1. Select all employees who work in the IT department.

• a) σ(Department = 'IT')(Employees)

• b) π(Department = 'IT')(Employees)

• c) σ(Department == 'IT')(Employees)

• d) π(Department == 'IT')(Employees)

Q1. Select all employees who work in the IT department.

• a) σ(Department = 'IT')(Employees)

• b) π(Department = 'IT')(Employees)

• c) σ(Department == 'IT')(Employees)

• d) π(Department == 'IT')(Employees)

Q2. Retrieve only the FirstName and LastName of employees from the table.

• a) π(FirstName, LastName)(Employees)

• b) σ(FirstName, LastName)(Employees)

• c) π(EmployeeID, FirstName, LastName)(Employees)

• d) π(FirstName, Department)(Employees)

Q9. Find all employees and their corresponding department names. If an employee's department is not specified, the department name should be "Unknown."

• a) Employees ⋈ Department

• b) Employees ⋈ Department (Employees.Department == Department.Department)

• c) Employees ⋈ Department (Employees.Department = Department.Department)

• d) Employees ⋈ Department (Employees.Department == Department.Department) ∪ Employees