CH8 of database

What is the action taken when a referential integrity constraint is violated by inserting, deleting, or modifying tuples?

• Ignore the violation and proceed

• Rollback the transaction

• Modify the constraint

Which command is used to remove a base table that is no longer needed?

• Drop table

• Remove table

• Delete table

What are the options available for actions in Referential Triggered Action?

• SET PRIMARY , SET FOREIGN , SET UNIQUE

• SET INDEX , SET CHECK , SET CONSTRAINT

• SET NULL , CASCADE , and SET DEFAULT

In table creation with foreign key references, which actions can be specified like SET DEFAULT and SET NULL?

• CREATE TABLE REF

• CREATE TABLE KEY

• CREATE TABLE EMP

What does the ALTER TABLE command do?

• Creates new table

• Deletes the entire table

• Modifies a base table by adding \ dropping columns , changing definitions , or adding \ dropping constraints

Which command is used to add a column to an existing table?

• MODIFY TABLE EMPLOYEE ADD JOB VARCHAR(12);

• ALTER TABLE EMPLOYEE ADD JOB VARCHAR(12);

• ADD COLUMN EMPLOYEE JPB VARCHAR(12);

When dropping a column using ALTER TABLE, which behavior can be chosen between CASCADE and RESTRICT?

• CASCADE drops constraints and views automatically

• CASCADE ensures data loss

• RESTRICT ensures no data loss

How can a constraint be dropped using ALTER TABLE?

• Use ALTER TABLE with DROP CONSTRAINT command , specify the constraint name

• Use ALTER with ADD CONSTRAINT command

• Use ALTER with MODIFY CONSTRAINT command

What is the purpose of the ALTER TABLE Command in SQL?

• command used in ALTER TABLE to remove a specified constraint

• basic SQL statement for retrieving information from a database

• Used to change constraints on a table by adding or dropping defined constraints

What does the DROP CONSTRAINT command do in SQL?

• command used in ALTER TABLE to remove a specified constraint

• used to change constraints on a table by adding or dropping defined constraints

• Basic SQL statement for retrieving information from a database