QueryDSL SQL implementation

[bwajtr]

Check here: https://github.com/querydsl/querydsl/tree/master/querydsl-sql

[bwajtr]

Anyone who'd like to do the QueryDSL implementation - it's basically about:
Setup QueryDSL within SpringBoot environment, Implementing DataRepository interface, adding new JUnit tests and write summary for QueryDSL in README.md