HomeDiagramsER diagramER: One-or-More to Zero-or-Many

ER: One-or-More to Zero-or-Many

At-least-one to zero-or-many relationship.

er-one-or-more-to-zero-or-many.mmd
erDiagram
  TEACHER }|--o{ COURSE : teaches
Output
ER diagram, Zombie Mermaid TEACHER (no attributes) COURSE (no attributes) teaches

More ER diagram examples

ER diagram, Zombie Mermaid CUSTOMER (no attributes) ORDER (no attributes) places
ER: Basic Relationship
ER diagram, Zombie Mermaid CUSTOMER PK int id string name UK string email date created_at
ER: Entity with Attributes
ER diagram, Zombie Mermaid ORDER PK int id FK int customer_id UK string invoice_number decimal total date order_date string status
ER: Attribute Keys (PK, FK, UK)
ER diagram, Zombie Mermaid PERSON (no attributes) PASSPORT (no attributes) has
ER: Exactly One to Exactly One (||--||)
ER diagram, Zombie Mermaid CUSTOMER (no attributes) ORDER (no attributes) places
ER: Exactly One to Zero-or-Many
ER diagram, Zombie Mermaid SUPERVISOR (no attributes) EMPLOYEE (no attributes) manages
ER: Zero-or-One to One-or-Many