ManyToMany field creation problem

[Mrinmoy Das]

Hi,

I have these tables

on apps/common/models.py


class UnitType(models.Model):
    title = models.CharField(max_length=50)

    def __unicode__(self):
        return u'%s' % self.title

class UnitPrice(models.Model):
    project = models.ForeignKey('property.Property')
    unit_type = models.ForeignKey(UnitType)

    five_year_target_price = models.CharField(max_length=50, blank=True, null=True)
    per_sqft_price = models.CharField(max_length=50, blank=True, null=True)
    total_price = models.CharField(max_length=50, blank=True, null=True)
   
    total_area = models.CharField(max_length=140, blank=True, null=True)
    carpet_area = models.CharField(max_length=140, blank=True, null=True)

     def __unicode__(self):
        return u'%s' % self.title

and on apps/property/models.py


class Property(Base):
.....
.....
    unit_price = models.ManyToManyField(UnitType,through=UnitPrice, blank=True, null=True)

.....
.....

after adding the unit price field I did  a migration

      python manage.py schemamigration property --auto

I am getting this output

       Nothing seems to have changed.

the through table is created,  i have checked that.


                                         Table "public.common_unitprice"
         Column         |          Type          |                           Modifiers                          
------------------------+------------------------+---------------------------------------------------------------
 id                     | integer                | not null default nextval('common_unitprice_id_seq'::regclass)
 project_id             | integer                | not null
 unit_type_id           | integer                | not null
 five_year_target_price | character varying(50)  |
 per_sqft_price         | character varying(50)  |
 total_price            | character varying(50)  |
 total_area             | character varying(140) |
 carpet_area            | character varying(140) |
Indexes:
    "common_unitprice_pkey" PRIMARY KEY, btree (id)
    "common_unitprice_project_id" btree (project_id)
    "common_unitprice_unit_type_id" btree (unit_type_id)
Foreign-key constraints:
    "project_id_refs_id_7c43d44c" FOREIGN KEY (project_id) REFERENCES property_property(id) DEFERRABLE INITIALLY DEFERRED
    "unit_type_id_refs_id_1a1f3765" FOREIGN KEY (unit_type_id) REFERENCES common_unittype(id) DEFERRABLE INITIALLY DEFERRED

Any help??

Mrinmoy Das
http://goromlagche.in/

[Daniel Roseman]

What else are you expecting? If the through table is created, that's all you need.

--

DR.

[Mrinmoy Das]

I cant get the field

unit_price = models.ManyToManyField(UnitType,through=UnitPrice, blank=True, null=True)

in Property table.

After adding the field, I tried doing a schemamigration, but output says  "No change has been done"

Mrinmoy Das
http://goromlagche.in/

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.
To post to this group, send email to django...@googlegroups.com.
Visit this group at http://groups.google.com/group/django-users.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/0b766e73-adf4-42a9-9085-524687de9f50%40googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

[Chi Tak Lam]

I think you should do a

python manage.py migrate property

after

python manage.py schemamigration property --auto?

[Mrinmoy Das]

Any help guys??

Mrinmoy Das
http://goromlagche.in/

--

You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.
To post to this group, send email to django...@googlegroups.com.
Visit this group at http://groups.google.com/group/django-users.

To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/96bce83f-11bf-453b-b6d9-db2b8644c6c4%40googlegroups.com.

[Daniel Roseman]

As I've already said, you don't need any help. If the through table is created, *that is all you need*.
--
DR.

[Mrinmoy Das]

Hi Daniel,

I can always add a field manually, question is why does not south does it. :)

Mrinmoy Das
http://goromlagche.in/

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.
To post to this group, send email to django...@googlegroups.com.
Visit this group at http://groups.google.com/group/django-users.

To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/8ef938a7-13f2-4b4f-9a2d-43c809f8eacb%40googlegroups.com.

[Daniel Roseman]

On Friday, 6 December 2013 19:15:32 UTC, Mrinmoy Das wrote:

Hi Daniel,

I can always add a field manually, question is why does not south does it. :)

Mrinmoy Das
http://goromlagche.in/

Sigh. One last time, then.

There is no other field. A many-to-many relationship is *only* a through table. Nothing else needs to be created, and nothing else will be created.

--

DR.

[Tom Evans]

On Fri, Dec 6, 2013 at 9:42 AM, Mrinmoy Das <mrinmo...@gmail.com> wrote:
> I cant get the field
>
>
> unit_price = models.ManyToManyField(UnitType,through=UnitPrice, blank=True,
> null=True)
>
> in Property table.
>
> After adding the field, I tried doing a schemamigration, but output says
> "No change has been done"
>

This is because adding that field results in no change - no columns
need to be added to any tables, no columns need to be removed from any
tables and no tables need to be created.

Adding the unit_price field to Property simply informs Django to
create the appropriate properties on the python models so that you can
access the related models, and so South, being a tool for managing
database schema changes, has nothing to do.

Cheers

Tom

[Mrinmoy Das]

Hi,

Sorry Daniel for bothering, my understanding of many to many field was pretty shaky :)