Types of Relationships in DBMS

Types of Relationships

A relationship represents the association between two are more entities. On this page, we will learn about different types of relationships in DBMS.
Types of Relationships in DBMS img

Types of Relationships in DBMS

  • The relationship also shows the different entity sets that are participating in a relationship, these relationships are very much useful for analyzing the design process of the system.
  • There are 5 types of relationships
    • Unary Relationship
    • Binary Relationship
    • n-ary Relationship
    • Recursive Relationship
    • Ternary Relationship
Types of Relationships in DBMS

Unary relationship

When there is only one entity set participating in a relationship then such type of relationship is called unary relationship

Example of unary relationship

For example, a person has only one passport and only one passport is given to only one person and hence unary relationship is observed

Entity Relationship Diagram in DBMS unary relation

Binary relationship

When there are exactly two  entity sets participating in a relationship then such type of relationship is called binary relationship

Example of binary relationship

For example, a teacher  teaches a  subject here 2  entities are teacher and subject for the   relationship  teacher teaches subject

Types of Relationships in DBMS binary

N-ary relationship

When a large number of entity sets  are participating in a relationship,  then such type of relationship is  called an n-ary relationship

Example of n-ary Relationship

In the real world, a patient goes to a doctor  and doctor prescribes the medicine and diagnosis  to the patient, four entities Doctor, patient and medicine, diagnostics  are involved in the relationship “prescribes” 

Types of Relationships in DBMS n-ary

Recursive relationship

A Recursive relationship is nothing but, simply an entity is having a relationship with self

Example of recursive Relationship
    • The person who is a supervisor for many other employees also come under employees category
    • Student can be a class monitor and handle other students but a person who is working as a class leader is itself a student of the class and hence a class monitor has a recursive relationship of entity student 
Types of Relationships in DBMS recursive

Ternary relationship

When there are exactly three entity sets participating in a relationship then such type of relationship is called ternary relationship

Example of Ternary Relationship

In the real world, a patient goes to a doctor  and doctor prescribes the medicine to the patient, three entities Doctor, patient and medicine are involved in the relationship “prescribes”

Types of Relationships in DBMS ternary

Prime Course Trailer

Related Banners

Get PrepInsta Prime & get Access to all 200+ courses offered by PrepInsta in One Subscription

Get over 200+ course One Subscription

Courses like AI/ML, Cloud Computing, Ethical Hacking, C, C++, Java, Python, DSA (All Languages), Competitive Coding (All Languages), TCS, Infosys, Wipro, Amazon, DBMS, SQL and others

Checkout list of all the video courses in PrepInsta Prime Subscription

Checkout list of all the video courses in PrepInsta Prime Subscription