PL/SQL User's Guide and Reference

Using PL/SQL Collections with SQL Statements
IF new_cost IS NOT NULL THEN
my_projects(i).cost := new_cost;
END IF;
EXIT;
END IF;
END LOOP;
UPDATE department SET projects = my_projects
WHERE dept_no = dept_id;
END update_project;
Example: Performing INSERT, UPDATE, and DELETE Operations on
PL/SQL Nested Tables
To perform DML operations on a PL/SQL nested table, use the operators TABLE
and CAST. This way, you can do set operations on nested tables using SQL notation,
without actually storing the nested tables in the database.
The operands of CAST are PL/SQL collection variable and a SQL collection type
(created by the CREATE TYPE statement). CAST converts the PL/SQL collection to
the SQL type.
The following example counts the number of differences between a revised course
list and the original (notice that the number of credits for course 3720 changed from
4 to 3):
DECLARE
revised CourseList :=
CourseList(Course(1002, ’Expository Writing’, 3),
Course(2020, ’Film and Literature’, 4),
Course(2810, ’Discursive Writing’, 4),
Course(3010, ’Modern English Grammar ’, 3),
Course(3550, ’Realism and Naturalism’, 4),
Course(3720, ’Introduction to Shakespeare’, 3),
Course(3760, ’Modern Drama’, 4),
Course(3822, ’The Short Story’, 4),
Course(3870, ’The American Novel’, 5),
Course(4210, ’20th-Century Poetry’, 4),
Course(4725, ’Advanced Workshop in Poetry’, 5));
num_changed INTEGER;
BEGIN
SELECT COUNT(*) INTO num_changed
FROM TABLE(CAST(revised AS CourseList)) new,
TABLE(SELECT courses FROM department
PL/SQL Collections and Records 5-25