Hi Mike, Thanks for all the work you are doing on Drill. To answer your question, sub1 should be treated as a map in Drill. You can verify this with the following query:
SELECT drillTypeOf(sub1) FROM... In general, I'm pretty sure that Drill doesn't output strings that look like JSON objects unless they actually are complex objects. Take a look here for data type functions: https://drill.apache.org/docs/data-type-functions/ Best, -- C > On Oct 10, 2023, at 7:56 AM, Mike Beckerle <mbecke...@apache.org> wrote: > > I am trying to understand the options for populating Drill data from a > Daffodil data parse. > > Suppose you have this JSON > > {"parent": { "sub1": { "a1":1, "a2":2}, sub2:{"b1":3, "b2":4, "b3":5}}} > > or this equivalent XML: > > <parent> > <sub1><a1>1</a1><a2>2</a2></sub1> > <sub2><b1>3</b1><b2>4</b2><b3>5</b3></sub2> > </parent> > > Unlike those texts, Daffodil is going to have a tree data structure where a > parent node contains two child nodes sub1 and sub2, and each of those has > children a1, a2, and b1, b2, b3 respectively. > It's analogous roughly to the DOM tree of the XML, or the tree of nested > JSON map nodes you'd get back from a JSON parse of that text. > > In Drill to query the JSON like: > > select parent.sub1 from myStructure > > gives you back single column containing what seems to be a string like > > | sub1 | > ---------------------- > | { "a1":1, "a2":2} | > > So, my question is this. Is this actually a string in Drill, (what is the > type of sub1?) or is sub1 actually a Drill data row/map node value with two > node children, that just happens to print out looking like a JSON string? > > Thanks for any insight here. > > Mike Beckerle > Apache Daffodil PMC | daffodil.apache.org > OGF DFDL Workgroup Co-Chair | www.ogf.org/ogf/doku.php/standards/dfdl/dfdl > Owl Cyber Defense | www.owlcyberdefense.com
