SQL Overview

SQL Tutorial 2: SQL Overview

SQL (Structured Query Language) is a touchstone linguistic communication for accessing databases.

All Relational Database Management Systems similar MS Access, MS SQL Server, Oracle, Sybase, MySQL, DB2 use SQL every bit touchstone database language.
-----------------------------------------------
i) Environment Setup

We tin practise SQL Commands inwards whatsoever Database Management System, Install whatsoever Database Engine similar Oracle, SQL Server, Sybase, MySQL etc... and practice.
-----------------------------------------------
ii) SQL Syntax

•  A database contains 1 or to a greater extent than tables. Each tabular array is identified yesteryear a name, Tables incorporate records (rows) with data.

•  Most of the actions nosotros postulate to perform on a database are done amongst SQL statements.

•  SQL keywords are NOT illustration sensitive: select is the same every bit SELECT

•  All the SQL statements rootage amongst whatsoever of the keywords similar SELECT, INSERT, UPDATE, DELETE etc...and all the statements terminate amongst a semicolon (;), semicolon is the touchstone agency to sort out SQL Statements.
-----------------------------------------------
iii) SQL Data Types

• A information type defines what variety of value a column tin contain, nosotros bring to usage information types piece creating database tables, select a item information type for a tabular array column based on our requirement.

Example:

Character Data Types,
Numeric Data Types,
Date as well as Time Data Types Etc...

Note: Data Types vary from One Database Management System to another
-----------------------------------------------
iv) Operators

Operators are used to perform Arithmetic, Comparison as well as Logical Operations.

Categories of Operators inwards SQL

1) Arithmetic Operators
2) Comparison Operators
3) Logical Operators
-----------------------------------------------
v) SQL Functions

SQL has many built-in functions for performing processing on data.

Categories of Built-in Functions inwards SQL

1) Aggregate Functions
2) String Functions
3) Date Functions Etc...
-----------------------------------------------
vi) Data definition Language

The Data definition Language (DDL) is used to do as well as destroy databases as well as database objects. 

Important Operations


• Create Database
• Use Database (Specify the Database you lot wishing to piece of employment amongst inside your DBMS.)
• Alter Database
• Drop Table, Drop Database
-----------------------------------------------
vii) Data Manipulation Language

The Data Manipulation Language (DML) is used to insert, yell back as well as modification database information.

Important Operations


• Insert Records to an existing Table
• Retrieve the specific information from an operational database. 
• Modify information contained inside a Table.
• Delete information contained inside a Table.
-----------------------------------------------
viii) Data Control Language

The Data Control Language (DCL) allows database administrators to configure safety access to relational databases.

Important Operations

• Provide access on the Database objects to the Users
• Remove User access rights to the Database Objects
• Deny Permissions to Users.
-----------------------------------------------
ix) SQL SELECT Statement

The SELECT contention is used to select information from a database.

• General Selection
• Conditional Selection Etc...
(We usage clauses, Operators as well as keywords...)
-----------------------------------------------
x) SQL Joins

The SQL Joins clause is used to combine records from ii or to a greater extent than tables inwards a database. 

Different SQL Joins:

1) Inner Join
2) Left Join
3) Right Join
4) Full Join
---------------------------------------------------------------------------------
Popular Database Management Systems

1) Oracle

Oracle database is a relational database administration organization (RDBMS) developed yesteryear Oracle Corporation. 

Important Oracle editions are, 

i) Enterprise Edition: Offers all features, including superior performance as well as security.

ii) Standard Edition: Contains base of operations functionality for users.

iii) Express Edition: The lightweight, complimentary as well as express Windows as well as Linux edition

iv) Oracle Lite: For mobile devices
----------------------------------------------------
2) Microsoft SQL Server

Microsoft SQL Server is a relational database administration organization developed yesteryear Microsoft.

Important Microsoft SQL Server editions are, 

i) Datacenter: SQL Server 2008 R2 Datacenter is a full-featured edition of SQL Server.

ii) Enterprise: SQL Server Enterprise Edition includes both the essence database engine as well as improver services.

iii) Standard: SQL Server Standard edition includes the essence database engine, along amongst the stand-alone services.

iv) Web: SQL Server Web Edition is for Web hosting.

v) Workgroup: SQL Server Workgroup Edition includes the essence database functionality only.
-----------------------------------------------------
3) MySQL

MySQL is an Open Source Relational SQL database administration organization used for developing web-based software applications.

Important MySQL Editions are, 

i) Standard Edition: Standard Edition enables us to deliver high-performance as well as scalable Online Transaction Processing (OLTP) applications.

ii) Enterprise Edition: Enterprise Edition includes the almost comprehensive fix of advanced features as well as administration tools.

iii) Cluster Carrier Grade Edition: Cluster enables users to encounter the database challenges of side yesteryear side generation web, cloud, as well as communications services amongst uncompromising scalability, uptime as well as agility.
--------------------------------------------------------------------------
4) PostgreSQL

PostgreSQL is a powerful, opened upward source database administration system. It runs on all major operating systems, including Linux, UNIX, Mac OS X, Solaris, as well as MS Windows.
----------------------------------------------------------------------------
5) MS Access

Microsoft Access is bundled every bit part of the Microsoft Office suite. It is simply available on the PC version. It is a desktop database organization because its functions are intended to live on run from a unmarried computer.
---------------------------------------------------------------------------------------------
SQL Tutorial 1: Introduction to SQL


Sumber http://www.gcreddy.com/
Post a Comment (0)
Previous Post Next Post