Question

This query is working to get the defects from a specific project:

        QueryRequest defectRequest = new QueryRequest("defect");
        defectRequest.setFetch(new Fetch("Project", "LastUpdateDate", "FormattedId", "SubmittedBy", "Owner"));
        defectRequest.setQueryFilter(new QueryFilter("Project.Name", "=", rallyProjectName));
        QueryResponse projectDefects = rallyApi.query(defectRequest);

But, it doesn’t work to get the defects from all the child projects of a parent project.

Answer 1

Instead of setting the project in the query filter use project scoping instead:

QueryRequest defectRequest = new QueryRequest("defect");
defectRequest.setFetch(new Fetch("Project", "LastUpdateDate", "FormattedId", "SubmittedBy", "Owner"));
defectRequest.setProject("/project/12345"); //The project oid for your project
defectRequest.setScopedDown(true);
QueryResponse projectDefects = rallyApi.query(defectRequest);