Tables and Keys

Question 1

Columns

Answer 1

Define a single attribute

Question 2

Row

Answer 2

Individual entry representing the principle subject of the table

Question 3

Primary Key

Answer 3

Attribute that uniquely identifies a specific row/entry. Typically the first column. Must be unique

Question 4

Surrogate (Primary Key)

Answer 4

Key that has no mapping to anything in the real world. (sequential employee ID number)

Question 5

Natural (Primary Key)

Answer 5

Key that has some purpose outside of the database. (social security number)

Question 6

Foreign Key

Answer 6

Stores a Primary Key helps define relationships between multiple DB tables. This also Includes new relationships to the Primary Key within the same table (get better definition)

Question 7

Foreign Key Relationships

Answer 7

Relationships between tables can be made more robust by abstracting a meaningful attribute from a table’s Primary Key and using that as another table’s Foreign Key link back to the original table

Question 8

Composite Key

Answer 8

A Key represented by two or more columns. The individual columns might repeat, but the composite will be unique

Question 9

Foreign Primary Composite Key

Answer 9

These most meaningful keys can create the logic for tables and represent additional data