DCL commands used to control the data access and database transaction control.
Grant: Grant command is used to assign privileges to users to access a database object.
Grant insert, update on student_info to HR_teacher;
Grant all on employees to system;
Grant on Column level:
Grant update(salary,commission)on employees to system;
Revoke: Revoke command is used to retrieve the privileges assigned to the users on a database objects.
revoke all on employee from system;
revoke insert, update on student_info from HR_teacher;
Revoke on column level:
Revoke update(salary,commission) on employees from system;