21.Say True or False. If False, explain why.
PL/SQL supports the CREATE command.
False. PL/SQL doesn’t support the data definition commands like CREATE.
12.What is returned by the cursor attribute SQL%ROWCOUNT?
It returns the number of rows that are processed by a SQL statement.
13.What is returned by the cursor attribute SQL%FOUND?
It returns the Boolean value TRUE if at least one row was processed.
14.What is returned by the cursor attribute SQL%NOTFOUND?
It returns the Boolean value TRUE if no rows were processed.
15.Which command/commands allow iteration a use of loops in a PL/SQL block?
LOOP command, FOR.. LOOP command, WHILE command.
16.What is the difference in execution of triggers and stored procedures?
A trigger is automatically executed without any action required by the user, whereas, a stored procedure needs to be explicitly invoked.
17.What are the uses of triggers?
Basically triggers are used to create consistencies, access restriction and implement securities to the database. Triggers are also used for −
Creating validation mechanisms involving searches in multiple tables
Creating logs to register the use of a table
Update other tables as a result of inclusion or changes in the current table.
18.Say True or False. If False, explain why.
Triggers can be associated to a view.
True.
19.Say True or False. If False, explain why.
When a trigger is associated to a view, the base table triggers are normally disabled.
False. When a trigger is associated to a view, the base table triggers are normally enabled.
20.Say True or False. If False, explain why.
A trigger can perform the role of a constraint, forcing an integrity rule.
True.
