Set process.element to null on corpus processes before corpus deletion

arkindex/documents/tasks.py

@@ -41,6 +41,10 @@ def corpus_delete(corpus_id: str) -> None:
         corpus.top_level_type_id = None
         corpus.save(update_fields=["top_level_type_id"])
 
+    # Set process.element to NULL in all processes, to avoid IntegrityErrors when deleting elements, as
+    # elements are deleted before processes.
+    Process.objects.filter(corpus_id=corpus_id).exclude(element_id=None).update(element_id=None)
+
     # Delete all related objects, bypassing RESTRICTs deletion rules
     # and Django's way of loading everything into memory before deleting.
     querysets = [

arkindex/sql_validation/corpus_delete.sql

@@ -10,6 +10,11 @@ FROM "documents_corpus"
 WHERE "documents_corpus"."id" = '{corpus_id}'::uuid
 LIMIT 21;
 
+UPDATE "process_process"
+SET "element_id" = NULL
+WHERE ("process_process"."corpus_id" = '{corpus_id}'::uuid
+       AND NOT ("process_process"."element_id" IS NULL));
+
 SELECT "django_content_type"."id",
        "django_content_type"."app_label",
        "django_content_type"."model"

arkindex/sql_validation/corpus_delete_top_level_type.sql

@@ -14,6 +14,11 @@ UPDATE "documents_corpus"
 SET "top_level_type_id" = NULL
 WHERE "documents_corpus"."id" = '{corpus_id}'::uuid;
 
+UPDATE "process_process"
+SET "element_id" = NULL
+WHERE ("process_process"."corpus_id" = '{corpus_id}'::uuid
+       AND NOT ("process_process"."element_id" IS NULL));
+
 SELECT "django_content_type"."id",
        "django_content_type"."app_label",
        "django_content_type"."model"