This is a simple app written in PHP that can be used to demonstrate how SQL injection vulnerabilities can be used to bypass a login page.
username: admin' -- //
password: anythinghere
username: ' or 1 -- //
password: anythinghere
username: suresh' -- //
password: anythinghere
admin:admin
bob:password
suresh:troll
ramesh:troll
alice:alice1
voldemort:horcrux
frodo:frodo
hodor:hodor
rhombus:rhombus