1. Oracle Academy Lead Adjunct
Prof. Carmen Popescu
Oracle Academy Lead Adjunct

2. Forma generala a comenzii SELECT
SELECT expresii
FROM tabele
WHERE conditii
In clauza select pot aparea coloane, sau expresii
Ordinea operatorilor: * / + -
Operatorii logici: AND, OR (in aceasta ordine)

3. BETWEEN SELECT * from employees WHERE department_id BETWEEN 10 AND 30
department_id >=10 AND
department_id<=30
Departamentul 20 ESTE afisat

4. IN SELECT * from employees WHERE department_id IN (10,30) 
department_id=10 OR
department_id=30
Departamentul 20 NU ESTE afisat

5. NULL
5+NULL => NULL
La ordonare crescatoare valorile NULL sunt puse la sfarsit
La ordonare descrescatoare NULL apare la inceput

6. ALIAS DE COLOANA (AS) SELECT salary+0.25*salary FROM employees
AS ”New Salary”
AS New Salary
=> EROARE

7. ALIAS DE COLOANA (AS) SELECT first_name||’ ’||last_name AS Numele
FROM employees
AS ”Numele”

8. ALIAS DE COLOANA (AS) Ghilimelele la alias sunt obligatorii cand:
Aliasul e compus din doua sau mai multe cuvinte
Dorim ca aliasul sa fie scriscu litere mici

9. DESCRIBE

10. LIKE SELECT * from employees WHERE first_name LIKE ’%a%’
afiseaza toate persoanele cu un ’a’ oriunde in prenume
WHERE first_name LIKE ’_ _a%’
afiseaza persoanele cu un a pe a treia pozitie din nume
% - oricate caractere (inclusiv nici unul)
_ - un singur caracter

11. LIKE SELECT * from employees WHERE job_title LIKE ’%\_ _ _’ ESCAPE ’\’
afiseaza persoanele pt. care in job_title, dupa caracterul _ mai exista exact doua caractere
Cu clauza ESCAPE am precizat ca% sau _ precedate de \ vor
fi tratate ca si caractere
normale ce trebuie sa
apara in text nu ca
wildchar.

12. ORDER BY SELECT * FROM employees ORDER BY last_name ASC, salary DESC
SELECT first_name,salary,
department_id
FROM employees
ORDER BY 2
Se sorteaza dupa a doua
expresie din clauza SELECT,
adica dupa salary