DATA BASES Team 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.

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