Entity Relationship Diagrams

from Mermaid記法のサンプルhttps://gyazo.com/b11fa5fbfc14d6106f16696e02c4878a

code:mmd

erDiagram

ACTOR {

number(22) actor_id PK

varchar2(45) first_name

varchar2(45) last_name

timestamp last_update

}

ACTOR ||--o{ FILM_ACTOR: ""

FILM_ACTOR {

number(22) actor_id PK, FK

number(22) film_id PK, FK

timestamp last_update

}

FILM ||--o{ FILM_ACTOR: ""

FILM {

number(22) film_id PK

varchar2(255) title

clob description

}

FILM ||--o{ FILM_CATEGORY: ""

FILM_CATEGORY {

number(22) film_id PK, FK

number(22) category_id PK, FK

timestamp last_update

}

CATEGORY ||--o{ FILM_CATEGORY: ""

CATEGORY {

number(22) category_id PK

varchar2(25) name

timestamp last_update

}

LANGUAGE |o--o{ FILM: ""

LANGUAGE {

number(22) language_id PK

char(20) name

timestamp last_update

}

上記はSakila写経

ER図ともいう