SELECT
se deklarasyon nan SQL itilize rekipere done ki sòti nan yon tab baz done.
Nou ka itilize SELECT
deklarasyon yo ka resevwa done ki sòti nan kolòn nan espesifye (yo) oswa tout kolòn yo.
SELECT
deklarasyon gen sentaks sa a:
SELECT column1, column2, ... FROM table_name;
Sipoze nou gen yon tab ki rele 'Anplwaye' ak done sa yo:
+------------+-----------+----------+------------+ | EmployeeID | FirstName | LastName | Department | +------------+-----------+----------+------------+ | 1
| Mark
| Otto
| Finance | | 2
| Jacob
| Thornton | IT
| | 3
| Su
| Bird
| Marketing | | 4
| Sam
| Burger | IT
| +------------+-----------+----------+------------+
Pou chwazi kolòn 'Depatman' nan tablo 'Anplwaye yo':
SELECT Department FROM Employees;
Sòti:
+------------+ | Department | +------------+ | Finance | | IT
| | Marketing | | IT
| +------------+
Pou chwazi 'Depatman' ak 'EmployeeID' kolòn nan tablo a 'Anplwaye':
SELECT EmployeeID, Department FROM Employees;
Sòti:
+------------+------------+ | EmployeeID | Department | +------------+------------+ | 1
| Finance | | 2
| IT
| | 3
| Marketing | | 4
| IT
| +------------+------------+
Pou chwazi tout kolòn ki nan tablo 'Anplwaye yo':
SELECT * FROM Employees;
Sòti:
+------------+-----------+----------+------------+ | EmployeeID | FirstName | LastName | Department | +------------+-----------+----------+------------+ | 1
| Mark
| Otto
| Finance | | 2
| Jacob
| Thornton | IT
| | 3
| Su
| Bird
| Marketing | | 4
| Sam
| Burger | IT
| +------------+-----------+----------+------------+
Nou ka filtre rezilta yo nan yon SELECT
rechèch lè l sèvi avèk WHERE
kloz.
Pou egzanp, yo chwazi tout anplwaye nan 'IT Depatman an' itilize:
SELECT * FROM Employees WHERE Department='IT'
Sòti:
+------------+-----------+----------+------------+ | EmployeeID | FirstName | LastName | Department | +------------+-----------+----------+------------+ | 2
| Jacob
| Thornton | IT
| | 4
| Sam
| Burger | IT
| +------------+-----------+----------+------------+
Menm jan an tou, yo chwazi tout Id anplwaye ki nan 'IT Depatman an' nou itilize:
SELECT EmployeeID FROM Employees WHERE Department='IT'
Sòti:
+------------+ | EmployeeID | +------------+ | 2
| | 4
| +------------+