hi @huhh,
there is a bug in N1QL DP4 for the parametrized query with named placeholders, it doesn’t work (which is why we used $1 format in our examples in the blog post).
it’s only true for querying via the POST interface with JSON request format, but that’s unfortunately the one we are using in the SDK (since it allows the maximum range of features to be used), so it may be the case that the same query works in cbq client.
Best workaround for Java is to use the $1 syntax. The issue was since fixed (Loading...) and should be available in the next public release of N1QL (either as a separate download or part of developer preview for next major version of Couchbase Server).
Simon