Introduction of SQL
What is SQL?
SQL is a (structured query language) is used to perform on operations stored in database and it is query language and if we want to run queries it retrieved the stored data from the database and the information of data is stored in the form of tables.
Database is designed to maintain the data in RDBMS(Relational database management system) and
RDBMS have become the most popular type of database system, this makes easy to locate and access specific values
within the database and the relational structure makes it possible to run queries across multiple tables at once and we can
modify and extract and search the information with in the database and the main purpose of database is to store data in structured way so that we can access it easily.
Important SQL statements
There are five types of statements
DDL (Data definition statement language)
DML(Data manipulation language)
TCL(Transactional control language)
DCL(Data control language)
DRL(Data retrieval language)