Participation constraint defines how much instances of an entity set can participate with another entity set.
Types of Participation Constraint
There are two types of participation, explain under,
1. Partial Participation
- Each entity in the entity set (i.e. Entity Set A) may or may not participate in the relationship is known as partial participation.”
- Partial participation represents through a single line between the entity set and relationship set.
- Partial participation is also known as optional participation.
2. Total Participation
- Each entity in the entity set (i.e. Entity A) must participate in at least one relationship instance in that relationship set is known as total participation.
- Total participation represents through double line between the entity set and relationship set.
- Total participation is also known as mandatory participation.
Let Explain with example
- According to Partial participation, there may exist some courses for which no enrollments are made.
- According to Total participation, each student must be enrolled in at least one course.