Some people are saying that we can merge A,B,C in a single table and m:n relation of A and C in another table having foreign key. Thus 2 tables are required. Where as another person is saying that A,B,C cannot be merged as if we merge A,B,C then it means that the A and C sharing the same row must have relation. So we need at-least 3 tables, one for AB another for BC and another one for AC. So which is correct? 2 tables or 3 tables. I am pretty much confused with this.
The issue is that it cannot really be answered unless you give more constraints.
It can be implemented using only one table. Ugly but doable. Each record would be the union o fields needed plus one “type” field. There will be very little of help from the database in keeping referential integritet.