I do not understand the gorm mapping between `DeVariantSubjectDetailCoreDb` and `DeSubjectSampleMapping`. Do you have `assay_id` column in `de_variant_subject_detail` table? I have not found any notion of such column in perl scripts which are used for data upload (https://github.com/j-hudecek/tranSMART-ETL/tree/master/Postgres/GPL%201.0/VCF).