Mermaid Test

flowchart TB
  A[Start] --> B{Decision}
  B -->|Yes| C[Continue]
  B -->|No| D[Stop]

erDiagram
  CUSTOMER }|..|{ DELIVERY-ADDRESS : has
  CUSTOMER ||--o{ ORDER : places
  CUSTOMER ||--o{ INVOICE : "liable for"
  DELIVERY-ADDRESS ||--o{ ORDER : receives
  INVOICE ||--|{ ORDER : covers
  ORDER ||--|{ ORDER-ITEM : includes
  PRODUCT-CATEGORY ||--|{ PRODUCT : contains
  PRODUCT ||--o{ ORDER-ITEM : "ordered in"

graph TD
    A([开始]) --> B[用户访问注册页面]
    B --> C{用户已注册？}
    C --> |是| D[用户输入登录信息]
    C --> |否| E[用户填写注册信息]
    E --> F[系统验证注册信息]
    F --> G{信息合法？}
    G --> |是| H[注册成功，跳转登录页面]
    G --> |否| I[注册失败，提示错误信息]
    H & I --> J([结束])
    D --> K[系统验证登录信息]
    K --> |正确| J
    K --> |错误| I