What is DataBase? – A Database is a collection of logically related information in an organized way so that it can be easily accessed, managed and updated.
Some other operations can also be performed on database such as adding, updating and deleting data. A Database could be simple as a single text file with a list of names or it could be complex as a large bunch of text files including some data.
What is DataBase?
Fundamentals of Database
For defining database, two terms, which are used frequently with database, should be known.
- Data – These are raw and unorganized facts that need to be processed such as digital representation of text, numbers, graphical images or sound. eg. a student’s test score is one piece of data.
- Information – When data is processed, organized, structured or presented in a given context to make it useful or meaningful, it it called information. eg. the class’s average score is the information that can be concluded from the given data.
What is DataBase?
Types Of Database
Databases are of three types, namely as follows
In this type of Database, data is represented as collection of records and relationships among data are represented as links.
In This type of database, data is organized in the form of tree with nodes. Nodes are connected via links.
This database is also known as Structured Database in which data is stored in the form of tables. Where, columns define the type of data stored in the table and rows define the information about the data.
What is DataBase?
Components of a Database
A Database consists of several different components. Each component listed, is called an Object. Within the file, you can divide your data into seperate storage containers called tables view, add and update table data that you want by using queries and analyse or print data in a specific layout by using reports.
Database components are described below
These are the building blocks or relation of any relational database model where all the actual data is defined and entered. Different types of operation are done on the tables such as storing, filtering, retrieving and editing of data. Tables consist of cells at the intersection of records (rows) and fields (columns), which are describe below
- Field – It is an area (within the record) reserved for a specific piece of data. eg. customer number, customer name, street address, city, state, phone number, current address, etc. Field of a table is also known as column.
- Record – It is the collection of data items of all the fields pertaining to one entity, ie. a person, company, transition, etc. Record of a table is also known as row or a tuple and the number of records in a relation is called the cardinality of that relation.
These are basically questions based on the data available in a database. A query consists of specifications indicating which fields records, and summaries a user wants to fetch from a databases. Queries allow you to extracts databases on the criteria that you define.
Although you can enter and modify data in datasheet view of tables but you neither control the user’s action very well nor you can do much to facilitate the data-entry process. To overcome the problems, forms are introduced Like tables, forms can be used to view and edit your data.
However , forms are typically used to view the data in an underlying table one record at a time. eg a user can create data entry forms that looks exactly like a paper form. People generally prefer to my enter data in a well-desined form. rather then a table.
When you wants to print those records which are fetched forms your databases, design a report. Access even a has a wizard to help produce mailing labels.
In a relational databases, data is stored in different tables with relationalships to each other. this tables communicate and share information, which facilitates data search ability, organisation and reporting. in the case of relational databases, a relational databases management system (RDBMS) Perfoms this tasks. and important features of this databases system in that a single databases can be spread across several tables.
e.g. Base, Oracle, DB2, SAP SyBase, Informix, etc.
these are the various types of databases languages
- Data Definition Language – (DDL) DDL is used to define structure of your tables and objects in databases. in DBMS, it is used to specify a databases schema as a set of definitions.
- Data Manipulation Language – (DML) DML provides various commands used to access and manipulate data in existing databases. This manipulation involves inserting data into data base tables, retrieving existing data, deleting data form existing tables and modifying existing data.
- Data Control Language – (DCL) DCL commands are used to assign security levels in databases which involves multiple user setups. they are used to grant defined role and access privelages to the users.
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