You can use the DELETE statement to remove rows from a table.
For example, the following example shows how all employees in department 20 are deleted.
SELECT ename, deptno FROM emp;
ename | deptno
--------+--------
SMITH | 20
ALLEN | 30
WARD | 30
JONES | 20
MARTIN | 30
BLAKE | 30
CLARK | 10
SCOTT | 20
KING | 10
TURNER | 30
ADAMS | 20
JAMES | 30
FORD | 20
MILLER | 10
(14 rows)
DELETE FROM emp WHERE deptno = 20;
SELECT ename, deptno FROM emp;
ename | deptno
--------+--------
ALLEN | 30
WARD | 30
MARTIN | 30
BLAKE | 30
CLARK | 10
KING | 10
TURNER | 30
JAMES | 30
MILLER | 10
(9 rows)
Be cautious when you execute a DELETE statement without a WHERE clause. The following example shows this type of statement:
DELETE FROM tablename;
This statement removes all rows from the specified table and leaves the table empty. The system does not request confirmation before this deletion.