Hi Shriram Toradmal,
Thank you for contacting us!
1. You can create custom operations, but not custom operators .
2. Unfortunately the Query Builder doesn’t support SQL query format but it supports QueryBuilder value to DynamicLinq expression if that may suit your needs.
DynamicLinq expression documentation:
https://www.htmlelements.com/docs/querybuilder-query-parser/
However if you really SQL query format we can make Custom Javascript Components Development for you.
If that suits you feel free to submit your enquiry with: sales@jqwidgets.com
Please, do not hesitate to contact us if you have any additional questions.
Best regards,
Yavor Dashev
Smart UI Team
https://www.htmlelements.com/