Relationship between tables with two foreign keys
Cretu Eusebiu
I have a users(id) table and a friends(user_id1, user_id2) where user_id1 and user_id2 are both foreign keys to the users table.
What relationship is this ?
I think is One to Many, but since I have the user id two times it's a bit confusing. (I have to make a diagram and don't know what relationship to use).
xmojmr
This UML class diagram describes the situation (yuml.me script (click to edit))
In UML terms the line's name is navigable association with known multiplicity.
In order to draw a diagram you don't need to give the relationship another "name"
本文收集自互联网，转载请注明来源。
如有侵权，请联系[email protected] 删除。
编辑于
相关文章
Related 相关文章
- 1
two foreign keys to same primary key select statement MYSQL
- 2
Joining two tables with one table having a different foreign key
- 3
Postgresql: How to relate data between two tables?
- 4
SQLite with NULLABLE foreign keys
- 5
SQL SELECT between two non-joinable tables
- 6
The relationship between SelectionDAG and SelectionDAGISel
- 7
即使Foreign_keys为ON，FOREIGN KEY约束也会失败
- 8
烧瓶foreign_keys仍然显示AmbiguousForeignKeysError
- 9
AmbiguousForeignKeysError 即使在指定 foreign_keys 之后
- 10
Is there any way to find out the tables relationship?
- 11
What is the relationship between the PhantomReference and ReferenceQueue?
- 12
Trying to add a foreign relationship to my users model with Devise, then update it
- 13
Symfony 2.3 Join tables using composite keys
- 14
Flask-SQLAlchemy-模型没有属性“ foreign_keys”
- 15
django“ use_natural_foreign_keys = True”问题
- 16
链接表中的SQLAclhemy foreign_keys错误[Flask]
- 17
Can't link two tables?
- 18
Two inner joins with same tables
- 19
Create ID automatically for all entries into tables with same foreign key
- 20
Designing a relationship between documents in Couchbase/CouchDB?
- 21
Check if two arrays share any common keys
- 22
Quickly merge tables with keys that are one-to-one and onto
- 23
Memory Management for Lookup Tables with string keys in C++
- 24
Entity framework one-to-many relationship - how to rename foreign key name when it is named Id?
- 25
Trying to insert into two tables using php and mysqli
- 26
Codeigniter, join of two tables with a WHERE clause
- 27
MySQL SELECT from two tables with COUNT
- 28
sqlite：如何在iOS中启用外键（PRAGMA foreign_keys始终返回0）
- 29
Laravel 6 PHPUnit测试-找不到驱动程序（SQL：PRAGMA foreign_keys = ON;）
我来说两句