SQL and Database Normalization Quiz

What does an inner join return?

• All rows from both tables

• Rows with at least one match in both tables

• Rows with no matches

• Only rows from the left table

What is the purpose of an outer join?

• To return only matching records

• To return all records from one table regardless of matches

• To delete records from a table

• To return all records from both tables

Which type of join returns all rows from the left table?

• Inner join

• Right join

• Left join

• Full join

What is a SQL view?

• A type of join

• A stored SELECT statement that can be treated like a table

• A table that contains data

• A method to delete data

What is one benefit of using SQL views?

• They can create calculated columns

• They cannot format data

• They increase data redundancy

• They require more complex queries

What does normalization aim to eliminate?

• Data types

• Data complexity

• Data security

• Data redundancy

What is a functional dependency?

• A way to delete data

• A type of SQL view

• A method to join tables

• A relationship between fields in a table

What is the first normal form (1NF)?

• All columns must be unique

• No multi-valued attributes in a table

• All non-key attributes are dependent on the primary key

• No repeating data in a table

What does the second normal form (2NF) require?

• All attributes must be dependent on the primary key

• No repeating data

• All columns must be unique

• No foreign keys

What is a characteristic of the third normal form (3NF)?

• Non-key attributes must depend on each other

• Every non-key attribute must be non-transitively dependent on the primary key

• It allows partial dependencies

• It requires repeating data