Cascaded detach of ManyToMany related objects does not work if there are no objects in relationship

[MartinHlavna]

Hello, I have exprienced issue with following model. I am using jaguar_query_sqflite as adapter.

1. Consider two entity models Post and Tag with ManyToMany relationship.
2. In jaguar_orm, this results in 3 objects. Post, Tag and PostTag object representing single relation between Post and Tag
3. Generated beans using jaguar_orm_gen are _PostBean, _TagBean and _PostTagBean
4. _PostBean contains method remove with cascade named parameter
5. If cascade = true, _PostBean calls postTagBean.detachPost(newModel);
6. postTagBean.detachPost has following code

   Future<int> detachPost(Post model) async {
   final dels = await findByPost(model.id);
   await removeByPost(model.id);
   final exp = Or();
   for (final t in dels) {
     exp.or(tagBean.id.eq(t.tagId));
   }
   return await tagBean.removeWhere(exp);
   }

7. Hovewer, if relationship is optional and we want to remove Post with no Tags this results in generating empty Or which is not valid SQL

[MartinHlavna]

PR #100 should fix this

[tejainece]

Published as jaguar_orm_gen version 2.2.24.