考虑到我有4个表:
- persons
- companies
- groups
- bills
变体1(多个关系表)
- persons_bills
- person_id
- bill_id
- companies_bills
- company_id
- bill_id
- groups_bills
- group_id
- bill_id
变体2(只有一个关系表,其中一个ID集为非空值,其他都为空)
- bills_relations
- person_id
- company_id
- group_id
- bill_id
变体3(只有一个关系表,其他表用字符串引用)
- bills_relations
- bill_id
- row_id
- row_table
变体4(添加一个超类型表)
- persons
- id
- debtor_id
- companies
- id
- deptor_id
- groups
- id
- deptor_id
- deptors
- id
- bills_deptors
- bill_id
- deptor_id