Database: SSS Three

Definition of Database and DBMS

Databas: Database is a collection of related data organized for rapid search and retrieval. It can also be defined as a persistent, logically coherent collection of inherently meaningful data, relevant to some aspects of the real world.
DBMS (Data Base Management System): DBMS is an application software that controls the data in the database, including overall organization, storage, retrieval, security and data integrity.

Examples of DBMS Packages

Dbase
Rbase
MS Access
Oracle
Paradox
MYSQL Server
SyBase
FOXPRO
IDMS
System 2000.
Ingres
Postgres
NoSQL

Basic Database Terminologies

Field: A field is a specific item of information containing a homogenous set of values throughout the table. Fields appear as columns in a table and as cells in a form.
Record: an individual listing of related information consisting of several related fields stored in a table. A record is also called a row in the datasheet.
File: this is a collection of records, for example, a school database.
Primary Key: A primary key is a field in a table whose value uniquely identifies each record in the table.
Fields that can serve as primary keys are:
Admission number
Matricultion number
BVN
Driving license number
phone number
Email address
Bank account number
Finger print
NIN, etc
Foreign keys: foreign key used to create relationships between tables.
Object: An object is a component of a database, such as a table, query, form, or report
a. Query: A query is a request for a particular collection of data in a database.
b. Report: a formatted collection of information organized to provide printed data on a specific subject.
c. Form: A form is a window or screen that contains numerous fields, or spaces to enter data
d. Table: In a database, a table is where all the data in the database is stored.

Forms of Database Organization

Different forms of database organization are:
1. Hierarchical
2. Network
3. Relational

Hierarchical
A hierarchical database model is a data model in which the data is organized into a tree-like structure. It can also be defined as a design that uses a one-to-many relationship for data elements. The data is stored as records are connected through links. Hierarchical database models link several disparate elements to one "owner," or "parent," primary record.

Network Database
A network database is a type of database model wherein multiple member records or files can be linked to multiple owner files and vice versa. In the network model of a database, a record can have multiple parents, making the system more flexible compared to the strict single parents of the hierarchical database.

Relational Database
A relational database presents information in tables with rows and columns. Records are arranged in rows while fields are arranged in columns. A relational database is the most common type of database structure. It is used by most microcomputers. The various software systems used to maintain relational databases are known as Relational Database Management Systems (RDBMS).

Features of Database Format
i. Files are designed as table
ii. Tables comprise rows and columns
iii. Rows contain related information about a record
iv. Columns contain a specific type of information about fields.

Steps in Creating Database
i. Define the structure
ii. Indicate the field type (numeric character, data, text, etc)
iii. Enter data
iv. Save data

Basic Operations on Already created Database

The following operations can be performed on an existing database
i. Searching
ii. Modifying
iii.Sorting
iv. Reporting
v. Selecting
vi. Inserting
vii Querying, etc