Class 10TH INFORMATIONAL TECHNOLOGY.pdf
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The document reviews database management systems (DBMS), highlighting their ability to manage large amounts of structured data, secure data access, and maintain data integrity. It discusses relational databases, data structures such as tables and fields, data types, and the two primary languages for manipulating data: Data Definition Language (DDL) and Data Manipulation Language (DML). Key features include reducing data redundancy, ensuring privacy and security, and enabling efficient data retrieval and management.
Class 10TH INFORMATIONAL TECHNOLOGY.pdf
- 1. Class 10 INFORMATIONAL TECHNOLOGY DATABASE MANAGEMENT A database management system (DBMS) is a computer program designed to manage a large amount of structured data, and run operations on the desired data requested by the users. The best example of DBMS is Banking. All the transactions that take place are based on a defined software program which keeps track of all the data. Advantages of Database: Some key features of a database: 1) A database can have one or many tables. 2) Each table in a database contains information about one type of item. Reduces Data Redundancy : no chance of encountering duplicate data Sharing of Data : the users of the database can share the data among themselves Data Integrity : Data integrity means that the data is accurate and consistent in the database Data Security : Only authorised users are allowed to access the database and their identity is authenticated using a username and password Privacy : The privacy rule in a database states that only the authorized users can access a database according to its privacy constraints Backup and Recovery : Database Management System automatically takes care of backup and recovery. Data Consistency : Data Consistency means there should be multiple mismatching copies of the same data.
- 2. 3) Every table has a key field which ensures that there are 100% unique values throughout the database. RDBMS:- A relational database management system (RDBMS) is a database management system that is based on the relational model. In the relational model of a database, all data is represented in terms of tuples (rows), grouped into relations (tables). A database organized in terms the relational model is a relational database. Database Concepts:- Database contains objects that are used for storing and managing information. TABLE :- A table is a set of data elements that is organized using a model of vertical columns and horizontal rows. Each row is identified by a unique key index or the key field. COLUMNS OR FIELD :- A column is a set of data values of a particular simple type, one for each row of the table. For eg. Emp_Code , Emp_Name , Emp_Address etc. Item : – Item is about which information is stored in the database. 1. Field:- Each question that we ask about our item is a Field. 2. Record:- Record is a set of information (made up of fields) stored in your database about one of the items. 3. Value:- Value is the actual text or numerical amount or date that you put in while adding information to your database. 4.
- 3. ROWS OR RECORDS OR TUPLES :- A row represents a single, data items in a table. Each row in a table represents a set of related data, and every row in the table has the same structure. DATA TYPES :- Datatypes are used to identify the type of data we are going to store in the database. Categories of data types:- Data types can be broadly classified into five categories:- NUMERIC TYPES:- They are used for describing numeric values like mobile number, age, etc. Numeric Types 1. Alphanumeric Types 2. Binary Types 3. Date Time 4. Other variable Types 5.
- 4. Alphanumeric Types : This data type is used to store information which has alphabets as well as numbers for example address, book summary field etc. The different types of Alphanumeric Types available are listed here. Binary Types : Binary data types are used for storing data in binary formats. Binary data types in a database can be using for storing photos, music files, etc.
- 5. DATE TIME : Date time data types in a database can be used for storing information such as date of birth, date of admission, date of product sale, etc. SESSION 3 MANIPULATING DATA : In a database we can define the structure of the data and manipulate the data using some commands. There are two types of languages:- 1. DDL (Data Definition Language) 2. DML (Data Manipulation Language) DATA DEFINITION / DESCRIPTION LANGUAGE:- It is a standard for commands that define the different structures in a database. DDL statements create,modify and remove database objects such as tables, indexes and users. Common DDL Statements are:- 1. Create :- Used to create database objects. 2. Alter :- Used to modify database objects. 3. Drop :- Used to delete database objects. DATA MANIPULATION LANGUAGE:- It is a standard for commands that enables users to access and manipulate data in a database. Common DML Statements are:- 1. SELECT :- Used for retrieval of information from the database. 2. INSERT :- Used for insertion of new information into the database.
- 6. 3. DELETE :- Used for deletion of information in the database. 4. UPDATE :- Used for modification of information in the database. Types of DML:- 1.Procedural:- The user specifies what data is needed and how to get it. 2. Non Procedural :- The user only specifies what data is needed. Note:- A popular data manipulation language is SQL (Structured Query Language.)