@startuml example-er
!include ./class-settings.puml
hide empty members

entity "Grade" as g {
  * id : varchar(200)
  --
  * created_at : datetime
  modified_at : datetime
  deleted_at : datetime
  * name : varchar(50)
  * year : varchar(5)
  * chief_teacher : varchar(200) <<FK>>
}

entity "Class" as cl {
  * id : varchar(200)
  --
  * created_at : datetime
  modified_at : datetime
  deleted_at : datetime
  * name : varchar(50)
  * grade_id : varchar <<FK>>
  * type : varchar(3)
  * chief_teacher : varchar(200) <<FK>>
}

entity "Member" as m {
  * id : varchar(200)
  --
  * created_at : datetime
  modified_at : datetime
  deleted_at : datetime
  disabled_at : datetime
  * name : varchar(50)
  * role : varchar(3)
  * username : varchar(50)
  * password : varchar(200)
}

entity "Teacher" as t <role="tea"> {
  * subject_id : varchar(200) <<FK>>
}

entity "Student" as st <role="stu">

entity "Teacher_Detail" as td {
  * teacher_id : varchar(200)
  --
  sex : varchar(3)
  birth : date
  entry_time : date
  phone : varchar(20)
}

entity "Student_Detail" as std {
  * student_id : varchar(200)
  --
  sex : varchar(3)
  birth : date
  enrolled_at : date
  graduated_at : date
  guardian_name : varchar(50)
  guardian_phone : varchar(20)
}

entity "Class_Student" as cls {
  * class_id : varchar(200) <<FK>>
  * student_id : varchar(200) <<FK>>
}

entity "Subject" as su {
  * id : varchar(200)
  --
  name : varchar(50)
}

entity "Work" as w {
  * id : varchar(200)
  --
  *created_at : datetime
  modified_at : datetime
  deleted_at : datetime
  * published_at : datetime
  * published_by : varchar(200) <<FK>>
  * subject : varchar(200) <<FK>>
}

entity "Class_Work" as cw {
  * class_id : varchar(200) <<FK>>
  * work_id : varchar(200) <<FK>>
}

entity "Work_Record" as wr {
  * work_id : varchar(200) <<FK>>
  * student_id : varchar(200) <<FK>>
  --
  * created_at : datetime
  modified_at : datetime
}

m <|-- t
m <|-- st
g --|| t
t ||- cl
g ||--|{ cl
su ||-o{ w
t ||--o{ w
cl ||--o{ cw
w ||-|| cw
su ||-o{ t
cl ||--o{ cls
st ||--o{ cls
w ||--o{ wr
st ||---o{ wr
td ||--t
std ||--st
@enduml