Oracle

  1->   How to create one to one relationship. Answer-> https://www.tutorialspoint.com/One-to-One-Relationship-in-DBMS#:~:text=One%2Dto%2DOne%20relationship%20in%20DBMS%20is%20a%20relationship%20between,of%20an%20entity%20with%20another.&text=An%20Employee%20is%20issued%20an,Card%20(ID_Card)%20are%20entities. One-to-One relationship  in DBMS is a relationship between an instance of an entity with another. An Employee is issued an Employee ID Card. An individual employee is offered a unique ID card in the company.  Here,  Employee  and I D Card (ID_Card)  are entities. A One-to-Many Unary Relationship is the association with the same entity between the same instances represented by different role groups. Consider the relationship between Managers and Employees.The two different Roles in this relationship are- Managers and Employees. Only few Employees take the role of Managers within an organization while everyone working for an organizat...