PPT Slide

SQL Query Extensions (by example)

• Substitutability

insert into emp

values (Emp_t('e100'), 'John Smith', 1968, 65000,

(select oid from dept where name = 'Database'));

update person set birthyear = birthyear + 1 where name = 'John Smith';

• Data modification (insert; update/delete)

select E.* from emp E

where E.birthyear > 1970 and E.salary > 50000;

• Path expressions

select E.name, E.dept->name

from emp E

where E.dept->mgr->dept->mgr->name = 'Lou Gerstner';

Previous slide

Next slide

Back to first slide

View graphic version