Updates to tables ■ Insert insert into instructor values ('10211','Smith','Biology,66000); ■Delete Remove all tuples from the student relation delete from student Drop Table ·drop table r ■Alter ·alter table radd A D where A is the name of the attribute to be added to relation r and D is the domain of A. All exiting tuples in the relation are assigned null as the value for the new attribute. ·alter table r drop A where A is the name of an attribute of relation r Dropping of attributes not supported by many databases. Database System Concepts-7th Edition 3.11 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 3.11 ©Silberschatz, Korth and Sudarshan th Edition Updates to tables ▪ Insert • insert into instructor values ('10211', 'Smith', 'Biology', 66000); ▪ Delete • Remove all tuples from the student relation ▪ delete from student ▪ Drop Table • drop table r ▪ Alter • alter table r add A D ▪ where A is the name of the attribute to be added to relation r and D is the domain of A. ▪ All exiting tuples in the relation are assigned null as the value for the new attribute. • alter table r drop A ▪ where A is the name of an attribute of relation r ▪ Dropping of attributes not supported by many databases