Dear Readers I have added some example codes for manipulating with the data in R. Someone may get familair with SQL statement I think it is pity easy and hope that it will be useful for you. In case you forget how to delete ,add or modify the data frame. I think my project will be another solution for your help

To practicing each statements, you might see the summary at the end of code. I think It is helpful to follow and help you to memorize the code.

Have a wonderful day Siroros R.