IT 221

Who proposed the Relational Model?

 

• Peter Chen

• Edgar F. Codd

• Raymond F. Boyce

• Ma. Esther B. Chio

What is the purpose of database normalization?

• Increase redundancy

•        Reduce redundancy and dependency

• Create complex relationships

• Remove all tables

Which SQL command is used to delete a table permanently?

• DELETE

• DROP TABLE

• REMOVE TABLE

• TRUNCATE

What is an entity in a database?

• A type of relationship

• A real-world object stored in the database

• A database model

• A set of primary keys

Which of the following SQL clauses is used to filter records?

• SELECT  

•   ORDER BY

• WHERE        

• DISTINCT

What does the primary key do in a table?

• Uniquely identifies each row

• Allows duplicate values

• Connects two tables

• Stores relationships

Which normalization form eliminates repeating groups?

• 1NF      

• 2NF        

• 3NF

• BCNF

Which of the following SQL operations is used to add a new record to a table?

• INSERT

• ADD

• UPDATE

• SELECT

What type of join returns only the matching rows between two tables?

• LEFT JOIN

•   RIGHT JOIN      

•    INNER JOIN

• FULL JOIN

What does the GROUP BY clause do in SQL?

• Filters records    

• Groups rows with the same values

• Orders rows

• Deletes duplicate records