would you please center this project around the us army i am a vetersn oif/oef..
ID: 3547121 • Letter: W
Question
would you please center this project around the us army i am a vetersn oif/oef.... thank you in advance
(1) Design the database using Entity-Relationship Diagrams/UML Class Diagrams.
(2) Create tables, including constraints such as primary keys, foreign keys, check constraints, and not null constraints.
(3) Create triggers and active elements to maintain integrity of the database and to perform appropriate actions on database updates.
(4) Populate the database using SQL insert statements or by writing programs in Java, VB, C#, Python, ASP.NET, JSP, or any language.
(5) Write application programs in any language.
(6) Documents the project.
The application programs would have to implement some form of user interface. The simplest user interface is terminal based and involves menus and sub-menus.
Explanation / Answer
(3) Create triggers and active elements to maintain integrity of the database and to perform appropriate actions on database updates.
In oracle data base we creating tiggers, to perform some actions and restrict the actions like INSERT, UPDATE, DELETE on database.
Examples.
CREATE OR REPLACE TRIGGER t
BEFORE
INSERT OR
UPDATE OF sal, deptno OR
DELETE
ON emp
BEGIN
CASE
WHEN INSERTING THEN
DBMS_OUTPUT.PUT_LINE('Inserting');
WHEN UPDATING('sal') THEN
DBMS_OUTPUT.PUT_LINE('Updating salary');
WHEN UPDATING('deptno') THEN
DBMS_OUTPUT.PUT_LINE('Updating department ID');
WHEN DELETING THEN
DBMS_OUTPUT.PUT_LINE('Deleting');
END CASE;
END;
/
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