Most databases display records as rows in a table or as forms., A record refers to a collection of data fields., A record has a template referred to as a record type and contains field names, but no data. Also, a data contained record is called a record occurance.
The smallest unit of meaningful information is called a field., A field name is designed to describe the field's contents., There are two types of length fields known as variable-length fields and fixed-length fields., Variable-length field expands to fit the data you enter, up to a max number of characters, Fixed-length fields contain a predetermined number of characters.
Allows one-to-one and many-to-many relationships, A one-to-one relationship means one record is related to many records, For example, in the case of a CD store, a customer can order many albums. Also, an album has only one description., A many-to-many relationship means that one record in a specific record type can be related to many records in another record type., For example, one album contains many songs, and a song can be included in a number of different albums, Rarely used in today's businesses, but are still used for specific applications.
Combines both one-to-one and many-to-many
Each table has a sequence of records, similar to that of a flat file., Two tables can be joined by similar fields., Tables are essentially independent, but can be joined to complete a particular task.
Each field is contained within a cell that can be accessed from a query or from following a relationship., Offers a simple way to visualize data and formulate queries.
Can easily store data about different types of orders., For example, a class called orders holds data and methods common to all types of orders. A class called web orders is common to only orders placed on the web.
Have the flexibility to store unique types of data and program code necessary to access that data., For example, a relational database sends a file name to an external player, but an object-relational database can store the song data and the routine to play it. Like iTunes.