Database Concepts

Anything that can have data stored about it, for example, a person, place, event, or thing.

• Entity

• Object

• Attribute

• Record

A situation in which one table in a database has a foreign key that refers to a primary key in another table.

• Association

• Relationship

• Connection

• Linkage

A candidate key that is an alternative to the primary key.

• Primary key

• Secondary key

• Foreign key

• Composite key

A structured collection of data items that can be accessed by different application programs.

• Database

• Spreadsheet

• Text file

• Data warehouse

It can be structured as a collection of records, where each record is made up of fields containing data about the same ‘thing’.

• file

• database

• table

• spreadsheet

An individual data item stored for an entity, for example, name, address, or date of birth.

• Attribute (database)

• Entity

• Record

• Field

The status of a relational database in which entities do not contain repeated groups of attributes.

• Second normal form (2NF)

• Third normal form (3NF)

• First normal form (1NF)

• Boyce-Codd normal form (BCNF)

A database where the data items are linked by internal pointers.

• Relational database

• Flat file database

• Object-oriented database

• Hierarchical database

An instance of an entity, represented by a row in a table.

• Row

• Tuple

• Column

• Field

An attribute or the smallest set of attributes in a table where no tuple has the same value.

• Primary key

• Foreign key

• Candidate key

• Composite key