Check all session and cursor aliases

[evlam]

Include additional try except to catch IndexErrors for nodes which do not have parents because they are not executing sql queries.

this py-find-injection will check all functions with the format *.execute because session.execute and cursor.execute may not be the only names used - in the case that the code uses aliases.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

Evell Lam seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}