Qlik MongoDB connector not supporting Multiple Column Subqueries

[fabdulazeez]

We are using Qlik MongoDB Connector to connect to mongodb to extract data. Each collection is availble as a table and each nested objects are available as independent table. Inorder to link those seperate Id's are generated at each level.

SQL like scripts are used to fetch the data. Currently we are facing the issue that theses SQL  is not supporting Multiple Column Subqueries, which make it difficult to fetch data from nested objects based on the parent object.

Like below query is throwing error 

select _id from child_table where (_id,nested_idx) in ( SELECT `parent_id`,nested_idx from parent_table where `source`='final');

@Vu_Nguyen Please support.

Note :  Error is field not found, but that one seems to be like some generic error when there is issue in the query.