What is Database? A database is a collection of information that is organized so that it can easily be accessed, managed, and updated. Is a tool for collecting and organizing information
Database program lets you: Store information Find information Analyze and print information Manage information Share information
Kinds of Databases Structured DatabaseIt is also called the structured data which a record or file of information is arranged in uniform format. Free-form databaseIt is a loose collection of information, such as those you will find on the World Wide Web.
Types of Databases Operational DatabaseA dynamic database that is used by any organization in its day to day operation. Analytical DatabaseIt is a static database, wherein data is often used to store and track historical data to make long term projection and analysis.
Structured Database Models Hierarchical model Network model Relational model Entity-relationship model Dimensional Model Object-relational model
Hierarchical Model Can be visualized as parent-child relationship wherein a child may only have one parent but a parent can have several children. Publisher AuthorsBookstore ManuscriptPaymentDeliveries
Network Model Publisher Authors Bookstore ManuscriptBook CategoryBook Launching ManageRepresent MakeArrange This model was developed to address in part the problems of the hierarchical model. This model allows sharing of branches but are still part of the same database structure.
Relational Model Developed by Dr. E.F. Codd of IBM in 1970s to solve the problems of the earlier database models as well as finding a way of making database management less dependent to any application. Publisher AuthorsBookstore BooksBook Arrangement Book Category
Relation = is a table with columns and rows Attributes = are the names given to each column of the relation. Domain = is the set of possible values which the attributes will take Tuples = usually represents an object and information about that object Terminologies
this model was written by Peter Chen in 1976. This model is an abstract and conceptual representation of data Entity-relationship model
Dimensional Model Is a specialized adaptation using the relational model that is used to represent data in data warehouses. Data warehouse storage of all digital data of a company or organization. Dimensions tells where, who and what type Measures means quality.
NAMEDESCRIPTION DataA number or value found and stored in the database. InformationA data that has been processed thereby making it relevant and meaningful NullUsed to represent a value that is unknown or missing.
TableThe main structure in the relational database FileAn organized collection of data about an entity. RecordRefers to a specific person, place or event. Also known as the tuple.
FieldThe smallest structure of a data from a larger database structure in a relational database. ViewKnown as the virtual table. It does not hold data on its own; rather it gets data from the table to which it is based.
KeysFields that serves specific purposes within a table. Primary key is a field that uniquely identifies a record in the table Foreign key is a special field that establishes a relationship between two tables. RelationshipsExist when two or more tables have connection and association.
Relationships Primary Key Foreign Key Linking table a table that establishes a connection between two or more table.
Types of Relationship One-to-One Relationship One-to-Many Relationship Many-to-Many Relationship
555-1289TalaidArmando003 555-6513NavalunaAlce002 555-8282GaleosRitchell001 PhoneLast NameFirst NameStudent ID One-to-One Relationship Mr. DacalosSt. Catherine003 Mr. TarayaSt. Dominic002 Ms. SatorSt. Thomas001 AdviserSectionStudent ID Students Table Sections Table
Designing a Database Define the purpose of your database Determine the tables that you need in the database. Determine the fields that you need in the database. Identify unique field values Determine the relationship between tables. Test the design by entering sample data.
Characteristics of a Well Designed Database Modify data easy. Retrieving information easy. Developing and building user application is easy. Maintaining the structure is easy. Adding and deleting data is easy.
Database Design to Avoid Spreadsheet design Spreadsheet view Building a database design on the database software