DATABASESTeam 3

Group 203

What is a DATABASE?

• A database is a collection of data from one context and systematically stored for later use.

• In this sense, a library can be considered a database comprised mainly of documents and printed on paper and indexed for reference.

• At present, due to technological development in fields such as computing and electronics, most of the databases are in digital format (e), which offers a wide range of solutions to the problem of storing data.

Database Classification

• Referential Database• Documental or Source Database

Referential Database

• It offers a representation of an original, or primary document.– Bibliographic– Electronic Phone Guide

Documental or Source Database

• It offers the complete, and original, or “base” document.– Numerical– Textual– Mixted

Interpretation

• A primary database contains the rough information in form of numbers, letters, combination of both creating a determined code, etc.

• A secondary database makes references of the primary databases, allowing to organize the information into an index or guide.

Static Database

• This are databases only for reading, used mainly to store storic data that can be used after, to study the behavior of a data group along the time, making proyeccions and take desicions.

Dynamic Databases

• This are databases where the stored information can be modified with the pass of the time, allowing operations as updating and data addition.

• An example of this type of databases we have the ones in the videoclubs.

A database model or database schema is the structure or format of a database, described in a formal language supported by the database management system.

DATABASE MODEL

It is a specification describing how a database is structured and used. Several such models have been suggested. Common models include:

• Hierarchical model • Network model • Relational model • Entity-relationship • Object-relational model • Object model

A data model is not just a way of structuring data: it also defines a set of operations that can be performed on the data. Although these operations may not be explicit in a particular query language, they provide the foundation on which a query language is built.

HIERARCHICAL MODEL

It’s a data model in which the data is organized into a tree-like structure. The structure allows repeating information using parent/child relationships: each parent can have many children but each child only has one parent. All attributes of a specific record are listed under an entity type.

A hierarchical database expects the hierarchical tables to be defined at design-time and does not expect them to be changed during run-time. The most recognized and used hierarchical database is IMS developed by IBM.

NETWORK MODEL

• It is a database model conceived as a flexible way of representing objects and their relationships.

• The network model's original inventor was Charles Bachman, and it was developed into a standard specification published in 1969 by the CODASYL Consortium.

NETWORK MODEL

Where the hierarchical model structures data as a tree of records, with each record having one parent record and many children, the network model allows each record to have multiple parent and child records, forming a lattice structure.

RELATIONAL MODEL

The relational model was introduced by E. F. Codd in 1970 as a way to make database management systems more independent of any particular application. It is a mathematical model defined in terms of predicate logic and set theory.

RELATIONAL MODEL

Three key terms are used extensively in relational database models:

• Relations: is a table with columns and rows

• Attributes: the columns of the relation• Domains: is the set of values the

attributes are allowed to take.

RELATIONAL MODEL

The basic data structure of the relational model is the table, where information about a particular entity is represented in columns and rows. Thus, the "relation" in "relational database" refers to the various tables in the database.

OBJECT-RELATIONAL

An object-relational database management system (ORDBMS) is a database management system (DBMS) similar to a relational database, but with an object-oriented database model: objects, classes and inheritance are directly supported in database schemas and in the query language.

OBJECT-ORIENTED MODEL

Developing a DATABASE.

• The most common program to develop databases is MICROSOFT ACCESS, so we’ll work on it.

http://msdn.microsoft.com/en-us/library/z0ac2676(VS.71).aspx

Planning the database

• The first step to making a database is to firstly plan one. This important step is often overlooked by eager beginners wanting to jump right in the deep end. However, without a clear plan, your database might end up a jumbled mess. Planning your project on paper will save you much frustration and dissapointment over the long run.

• Click here to watch the video

Start Microsoft Access and begin building a database

• When Microsoft Access first loads, you will notice a blank empty program. For some unknown reason the developers presumed users would automatically know what to do next. However this isn't always the case.

• Click Here to watch the video

Creating Table

• Below, some links to watch how to create some tables for your database.

• Part one• Part two• Part three• Part four

Adding Records

• Once you have a database table built, its time to add some records. Or in other words, add some customers.

• Click here to watch the video

Uses:• The Databases are the preferred

method of storage for large multiuser applications, where coordination between many users is needed.

• Even individual users find them convenient, and many electronic mail programs and personal organizers are based on standard database technology.

• Providing knowledgeable customer service

• Make products and services tailored to customer preferences

• Develop individualized, targeted marketing programs

• Conduct one-on-one dialogs with each customer

• Enlisting loyal customers in referral programs

• Classify customers by interests and profitability so as to give special attention to those most likely to build the bottom line

• Devise effective marketing programs to new prospects