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@QuantumGhost
Last active March 23, 2024 22:39
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A simple template for PlantUML to draw ER diagram.The basic idea comes from http://plantuml.sourceforge.net/qa/?qa=331/database-modeling
@startuml
' uncomment the line below if you're using computer with a retina display
' skinparam dpi 300
!define Table(name,desc) class name as "desc" << (T,#FFAAAA) >>
' we use bold for primary key
' green color for unique
' and underscore for not_null
!define primary_key(x) <b>x</b>
!define unique(x) <color:green>x</color>
!define not_null(x) <u>x</u>
' other tags available:
' <i></i>
' <back:COLOR></color>, where color is a color name or html color code
' (#FFAACC)
' see: http://plantuml.com/classes.html#More
hide methods
hide stereotypes
' entities
Table(user, "user\n(User in our system)") {
primary_key(id) INTEGER
not_null(unique(username)) VARCHAR[32]
not_null(password) VARCHAR[64]
}
Table(session, "session\n(session for user)") {
primary_key(id) INTEGER
not_null(user_id) INTEGER
not_null(unique(session_id)) VARCHAR[64]
}
Table(user_profile, "user_profile\n(Some info of user)") {
primary_key(user_id) INTEGER
age SMALLINT
gender SMALLINT
birthday DATETIME
}
Table(group, "group\n(group of users)") {
primary_key(id) INTEGER
not_null(name) VARCHAR[32]
}
Table(user_group, "user_group\n(relationship of user and group)") {
primary_key(user_id) INTEGER
primary_key(group_id) INTEGER
joined_at DATETIME
}
' relationships
' one-to-one relationship
user -- user_profile : "A user only \nhas one profile"
' one to may relationship
user --> session : "A user may have\n many sessions"
' many to many relationship
' Add mark if you like
user "1" --> "*" user_group : "A user may be \nin many groups"
group "1" --> "0..N" user_group : "A group may \ncontain many users"
@enduml
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@startuml
' uncomment the line below if you're using computer with a retina display
' skinparam dpi 300
!define Table(name,desc) class name as "desc" << (T,#FFAAAA) >>
' we use bold for primary key
' green color for unique
' and underscore for not_null
!define primary_key(x) <b>x</b>
!define unique(x) <color:green>x</color>
!define not_null(x) <u>x</u>
' other tags available:
' <i></i>
' <back:COLOR></color>, where color is a color name or html color code
' (#FFAACC)
' see: http://plantuml.com/classes.html#More
hide methods
hide stereotypes
' entities
' relationships
@enduml
@xinyifly
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Have you gave Information Engineering notation a try? https://plantuml.com/ie-diagram

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