erDiagram
  CUSTOMER {
    string name PK
    string email UK
    int age
  }
  ORDER {
    int id PK
    string status
  }
  CUSTOMER ||--o{ ORDER : places
---
+-----------------+      +------------------+
| CUSTOMER        |      | ORDER            |
+-----------------+      +------------------+
| PK string name  ||---o<| PK int id        |
| UK string email |places|    string status |
|    int age      |      +------------------+
+-----------------+