query operator as lowercase to escape casesensetive troubles.

[sergoslav]

Hi @pdphilip, I have got issue when using your extension together with Laravel lighthouse extension - it makes query builder with upper case operators (eg. LIKE) but your extension allows only lower case operators. So I added a hotfix to convert all operators to lowercase. And it solves my problem.

I'm not sure which one of extensions better to apply this fix, but maybe this hotfix would help to someone else escape such troubles in future.

Thank you!