How is sql important for sql injection?

Question

actually i want to be an ethical hacker and i am learning html, js, css ,php and sql. but i dont get a point in sql and sql injection. please help...

Answer 1

when you check the table and make column, and to dump specific column , you can use there

Answer 2

okay, this means i should complete this course right?

Answer 3

as much as you will learn you will gather more experience and ................................................................................................