SQL Introduction

SQL (StructuredQueryLanguage) is a database computer language designed for managing

Data in relational database management systems (RDBMS). SQL, is a standardized computer language that was originally developed byn IBM for querying, altering and defining relational databases, using declarative statements.  SQL is not case sensitive

What is SQL used for mainly in following purpose

Ø  To create new databases   ,  create new tables in a database , insert records in a database , update records in a database , retrieve data from a database , delete records from a database , execute queries against a database , create views in a database , create stored procedures in a database ,  set permissions on tables, procedures, and views , Modify  procedures , queries , triggers and Database etc.

Ø  To develope a website SQL play a very important role for Database activity

RDBMS

RDBMS stands for Relational Database Management System. RDBMS is the basis for SQL, and for all modern database systems like MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access. The data in RDBMS is stored in database objects called tables. A table is a collection of related data entries and it consists of columns and rows

Database Tables :

  A database can have one or more tables. Each table is identified by a name (e.g. "Customers" or "Orders"). Tables contain records  in the form of  rows and columns .

Example Of Table:  Below is an example of a table called "Persons", The table  contains three records (one for each person) and five columns (P_Id, LastName, FirstName, Address, and City).

 

P_Id	LastName	FirstName	Address	City
1	Suhail	Osmani	Maharaj Nagar	Sitapur
2	Maxwel	Tom	Biswan	Sitapur
3	Rahi	Ayon	Okhla	Delhi