DELETE FROM table-name WHERE predicate: You must be careful when "deleting" to not delete a primary key 
from one table which is referenced by a foreign key in another table.

example:1)To delete from Enrollment all records for a aprticular student

	DELETE 
	FROM       enroll
	WHERE    stuid = '135792468';
           This deletes from enroll all the records corresponding to student with an id 135792468.

        2). This deletes  from Enrollment all records for student named "Clinton".

        DELETE
	FROM       enroll
	WHERE    stuid =
	(SELECT    stuid
	FROM         student
	WHERE      stuname = 'clinton') ;