Error: Cannot get entity metadata for the given alias

Issue type:

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

Database system/driver:

[ ] cordova [ ] mongodb [ ] mssql [ ] mysql / mariadb [ ] oracle [x] postgres [ ] cockroachdb [ ] sqlite [ ] sqljs [ ] react-native [ ] expo

TypeORM version:

[x] latest [ ] @next [ ] 0.x.x (or put your version here)

Steps to reproduce or a small repository showing the problem: Hi. I’m having an issue with retrieving documents from a nested FROM-clause like this:

let query = getConnection().createQueryBuilder()
            .from((qb) => {
                    return qb
                        .from(A, "a")
                        .limit(1);
                }
                , "alias")

And get the error Cannot get entity metadata for the given alias "alias". Also, if I try to add another from:

.from(A, "b")

the query works, but the second FROM doesn’t replace the first one, as specified in the docs. How can I do this the right way? Thanks