My question would be can you help me with the code (if it possible all of it)

While you will get for sure help on concrete programming questions, I'm a bit puzzled why you didn't present already part of the code you already have written. May I ask you your background as a programmer? I assume that you already have programming experience in some other programming language (otherwise I don't think someone would have asked you to do such a task), but how is your Perl experience? In case you have never written a Perl program at all, I strongly suggest to spend at least 1-2 days learning the basics of Perl before starting on a real-world problem.

the table where we suppose to import that value doesn't have a columm with value T as a temperature so it will need to create that to.

Aside from the fact that, as you can do a SQL insert statement from Perl, you can do equally well do a SQL modify table statement from Perl, do you really want to create a new column every time the program is run???? Usually, the table is created beforehand (which you can conveniently do outside of Perl), so I still don't see the advantage of having a CSV file.