Issue type:

[ ] question
[ ] bug report
[x] feature request
[ ] documentation issue

TypeORM version:

> yarn list typeorm                        # service-graph -> feature/RS2-1053-deliverables-product-resolver $ !
yarn list v1.22.4
warning Filtering by arguments is deprecated. Please use the pattern option instead.
└─ typeorm@0.2.25
✨  Done in 1.17s.

Steps to reproduce or a small repository showing the problem:

I just want to be able to write

    this.createQueryBuilder('a')...getOneOrFail()

so my more complex query can behave the same way with the same exception type as a simpler query.