I have a confusion between one to many and many to one mapping.If state-city relation is one to many then city-state relation will be many to one.So it is the same thing from other end.One to many is many to one from other end and same way many to one is one to many from other end. so we have to never implement many to one relation because to implement that we can do one to many from other end.Please correct me if I am wrong.Thanks.
I didn't understand very well what you wrote. For me many to one means
Table that represents side MANY has foreign key column whose values point to primary keys in table on ONE side. Many rows on MANY side point to single primary key on ONE side table.
And one to many relation says that primary key on ONE side is pointed many times on MANY side table by foreign key column.