a$)$ SQL statements can be grouped into $3$ areas $-$ DDL$,$ DML and DOL. Outline the role of

DDL statements, DML statements and DCL statements. Give examples of all statements.

b$)$ Outline the role of a trigger in maintaining a unique identifier on a table. What are the

steps and requirements in implementing such a solution?

c$)$ Show the code to create a table called PRODUCT with two columns PROD$\_$D and

P R O DDESCRIPTION. Show the code tocreate sequence to be used to populate the

PROD$\_$ID primary key on the PRODUCT Table. Show the code to create a trigger to

populate the PROD$\_$ID primary key on the PRODUCT table using asequence.

d$)$ What is PL$/$SQL$?$ How can it beused in a database and in application development?

e$)$ Write an anonymous PL$/$SQL block to display the following $-$

Hello There

Today is today's date

Tomorrow istomorrow's date

Goodbye