MySQL

Introduction Of MySQL

Start with MySQL Server

Syntax In MySQL

Select In MySQL

Distinct In MySQL

Where In MySQL

And & Or In MySQL

Order By In MySQL

Insert Into In MySQL

Update In MySQL

Delete In MySQL

Injection In MySQL

Select Limit In MySQL

Like In MySQL

Wildcards In MySQL

Aliases In MySQL

Joins In MySQL

Inner Join In MySQL

Left Join In MySQL

Right Join In MySQL

Union In MySQL

Create DB In MySQL

Create Table In MySQL

DataTypes In MySQL

Normalization

Functions In MySQL

Keys & Level of Abstraction

Codd's Twelve Rules

MySQL subjective question

MySQL Interview question

MySQL Objective question

MySQL FAQS

RDMS FAQS

Oracle Interview Questions

SQL Injection is can use to prevent the malicious attack by another user to save your data. But it more use is done in the process of exploitation

Injection can be done like while you are entering your email id and password for login, SQL query is inject its SQL commands into its statement. It can alter the SQL statement but provides the security for a web application.

Syntax

SELECT * 
FROM tablename 
WHERE Clause INJECTION insertion;

basic SQL Injection Insertion can be done by three ways

Example

SELECT *
FROM studinfo
WHERE 1 = 1 ;

Display all reuslt from the table Studinfo

Example

SELECT *
FROM studinfo
WHERE fnama='arun' OR 1 = 1 ;

show the result on the basis of condition define fname='arun' and all result also display

Example

SELECT *
FROM studinfo
WHERE fnama='arun' OR 1 = 0 ;

show the result on the basis of condition define fname='arun' and single result will display whose condition is true.

Example

SELECT *
FROM studinfo
WHERE fnama='arun' AND 1 = 0 ;

If we can insert AND inplace of OR ,no result will be shown whose command will be given , because no condition will be true.

Example

SELECT *
FROM studinfo
WHERE fnama='arun' AND 1 = 1 ;

show the result on the basis of condition define fname='arun' and single result will display in which both condition is true.

The injection help in another ways they are used in some login page to check the validations which provides the security for a web application, like syntax is given below

Syntax

uname = getRequestString("Uname");
upass = getRequestString("UPass");
sql = "SELECT * FROM tablename
	 WHERE Name ='" + uname + "' 
 AND Pass ='" + upass + "'";

Example

SELECT *
FROM studinfo 
WHERE fname='arun' AND " " = " " 
	 AND lname='saxena' and " " = " ";

In this query both the condition needs to be valid to print the info, if one of the condition is false it does not show any result