Relationships in Databases


We use the word relationship to describe a variety of human connections. It encompasses romantic and nonromantic connections. However, no two people will have the same definition of what a relationship is. Nevertheless, this article explores some basic terms for understanding how relationships work. This article is divided into several sections.

Relationships between people

The relationships between people are not created by nature. Rather, they are created by organizations. In this way, we can control the nature of these relationships. For instance, a government can control the relationships between people through legislation, or by setting up a central contract. Governments have the power to enforce the agreements and they can also make the agreements binding.

A marriage is a legal and social commitment between two people. A relationship between two people is called a polygamous marriage if there are multiple partners involved. There are many different types of relationships between people, including polygamy, polyamory, and casual relationships.

Relationships between tables

Relationships between tables exist in many forms. A one-to-one relationship, for example, refers to a single record in a table having the same primary key value. This relationship is often forced by business rules, and does not flow naturally from the data. For this reason, it is important to design your database carefully and choose the right relationships for your specific data.

A foreign key is a field in one table that appears in another table. For example, a customer may have a Customer ID in the Customer table, and a Book ID in the Orders table. Creating a foreign key is a more straightforward process when you use the drag-and-drop method. This saves you a few steps and is faster.