how to description FK which contains more than 1 field

[Holland_zwz]

Hi all,

   I have 2 tables, one is A another is B, and B have one FK which contains more than 1 field references to A. The table struct is here:

create table A

(

  oid int not null,

  types varchar(20) not null,

  name varchar(30) null,

  color varchar(20) null,

  constraint PK_A primary key (oid,types)

)

create table B

(

 oid int not null,

 types varchar(20) not null,

......

)

alter table alter B  add constraint B_FK foreign key (oid,types) references A(oid,types) 

The how can i description the ModelB'f FK in Model?

class ModelA(models.Model):

    oid = models.IntegerField(max_length=10, primary_key=True)

    name = models.CharField(max_length=30,  primary_key=True)

    ....

class ModelB(models.Model):

    oid = models.ForeignKey(ModelA, to_field='oid')

    types = models.ForeignKey(ModelA, to_field='types')

    ...

However, this give errors, and not works.

Regards,

Hollandz

[Dario Concilio]

Hi again...
I could need to read this https://code.djangoproject.com/wiki/MultipleColumnPrimaryKeys
 
Bye
Dario
 

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Date: Mon, 10 Aug 2015 02:39:12 -0700
From: holla...@gmail.com
To: django...@googlegroups.com
Subject: how to description FK which contains more than 1 field

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[Dario Concilio]

Hi hollandzwz,
try to change to_field in related_name="entitites"
 
Example:
 
class UserFollower(models.Model):
    user_id = models.ForeignKey(User,related_name="users")
    follower_id = models.ForeignKey(User,related_name="followers")
 
bye
Dario Concilio

 

---

Date: Mon, 10 Aug 2015 02:39:12 -0700
From: holla...@gmail.com
To: django...@googlegroups.com

Subject: how to description FK which contains more than 1 field