Sql

DATA:-

Data is anything that can be represented as text, numbers or multimedia(image,sound,video etc)

              Ex: ‘Technology’, 243589, ‘2024-08-05’

DATA SET:-

              Dataset is a structured colletion of data ed colletion of data tha contains information of an entity

Ex:-      

cust_id	cust_name	Age	email	phone
1	Vishwa	29	jdsv@gmail.com	+91

                            

DATABASE:-

              Database is a system that allow users to store,organize and analyze data, it is an organized collection of data stored in multiple related datasets,

                             EX:-

RDBMS:- (Relational Data base Management System)

              A relational Database is data base that stores that in a table form,containing columns and rows.

RDBMS is a system use to store, manage,query, and retrieve data stored in a relational databases.

The RDBMS provides an interface between users&applications and the database.

LIST OF RDBMS SYSTEMS:-

Oracle

MySQL

Teradata

SQL Server

PostgreSQL

Vertica

IBM DB2

Snowflake(Cloud Database)

WHAT IS TABLE :-

              Table is a database object that is a collection of related data entries, where data is organized in rows and columns

Rows are also knw as records

Columns are also known as Fields

Example: Customer table

Metadata : Data about data it gives the info that what data is stored in a table.

HOW TO ACCES THE DATA FROM DATABASE :

SQL -Structured Query Language

v  We can access and manipulate the data from relational database by using SQL

v  Sql is a programming laguage used to communicate with these RDBMS systems like Oracle,Teradata,MySQL,SQL server etc.

v  SQL is an ANSI/ISO standard. All database support ANSI SQL so the syntaxes,keywords and funcions or almost similar in all databases.

v  We can build SQL queries and procedures too operate with the data present in Database.

v  Queries can be written by using Operators,keywords,Expressions,Fuctions..

DATA TYPES :-

Data types specify the type of the data we storing or querying

There are many data types to store

¨     Text(Characters,strings)

¨     Numeric values

¨     Date and time values

¨     Boolean (True or false)

¨     Images,audio,video data