SQL Basics
Dr. Sanjeev Verma
IMS, University of Lucknow,
Lucknow - 226021
, What is SQL?
• SQL stands for Structured Query Language. It is
used for storing and managing data in Relational
Database Management System (RDBMS).
• It is a standard language for Relational Database
System. It enables a user to create, read, update
and delete relational databases and tables.
• All the RDBMS like MySQL, Informix, Oracle, MS
Access and SQL Server use SQL as their standard
database language.
• SQL allows users to query the database in a
number of ways, using English-like statements.
,What are the SQL?
SQL follows the following rules:
• Structure query language is not case sensitive. Generally,
keywords of SQL are written in uppercase.
• Statements of SQL are dependent on text lines. We can
use a single SQL statement on one or multiple text line.
• Using the SQL statements, you can perform most of the
actions in a database.
• SQL depends on tuple relational calculus and relational
algebra.
, What is SQL Process?
• When an SQL command is executing for any RDBMS,
then the system figure out the best way to carry out
the request and the SQL engine determines that how
to interpret the task.
• In the process, various components are included.
These components can be optimization Engine, Query
engine, Query dispatcher, classic, etc.
• All the non-SQL queries are handled by the classic
query engine, but SQL query engine won't handle
logical files.
Dr. Sanjeev Verma
IMS, University of Lucknow,
Lucknow - 226021
, What is SQL?
• SQL stands for Structured Query Language. It is
used for storing and managing data in Relational
Database Management System (RDBMS).
• It is a standard language for Relational Database
System. It enables a user to create, read, update
and delete relational databases and tables.
• All the RDBMS like MySQL, Informix, Oracle, MS
Access and SQL Server use SQL as their standard
database language.
• SQL allows users to query the database in a
number of ways, using English-like statements.
,What are the SQL?
SQL follows the following rules:
• Structure query language is not case sensitive. Generally,
keywords of SQL are written in uppercase.
• Statements of SQL are dependent on text lines. We can
use a single SQL statement on one or multiple text line.
• Using the SQL statements, you can perform most of the
actions in a database.
• SQL depends on tuple relational calculus and relational
algebra.
, What is SQL Process?
• When an SQL command is executing for any RDBMS,
then the system figure out the best way to carry out
the request and the SQL engine determines that how
to interpret the task.
• In the process, various components are included.
These components can be optimization Engine, Query
engine, Query dispatcher, classic, etc.
• All the non-SQL queries are handled by the classic
query engine, but SQL query engine won't handle
logical files.
