Dec 15th, 2016: On db.v2, upper-db produced queries that mutated themselves:
q := sess.SelectFrom("users")
q.Where(...) // This method modified q's internal state.
Starting on db.v3 this is no longer valid, if you want to use values to
represent queries you'll have to reassign them, like this:
q := sess.SelectFrom("users")
q = q.Where(...)
q.And(...) // Nothing happens, the Where() method does not affect q.
This applies to all query builder methods, db.Result, db.And and db.Or.
If you want to check your code for statatements that might rely on the old
behaviour and could cause you trouble use dbcheck:
go get -u github.com/upper/cmd/dbcheck
dbcheck github.com/my/package/...