get field name from one app to another app in django - django

Question

We have defined two apps: Manin_matrix and SW_matrix.
We want the field name (project_name) present in class GENERAL_t of models.py file inside Main_matrix app to be inside the models.py file of SW_matrix app.
Basically, project_name_work field in class EDVT of SW_matrix models.py should be the same as project_name of Main_matrix app.
We want this so that in a database for EDVT table we will get the same project id along with the project name.
Main_matrix/models.py
class GENERAL_t(models.Model):
project_name = models.CharField(
blank=True,
null=True,
max_length=40,
verbose_name='Project_Name'
)
platform = models.CharField(
blank=True,
null=True,
max_length=40,
verbose_name='Platform SW'
)
SW_matrix/models.py
class EDVT(models.Model):
project_rel=models.ForeignKey(
GENERAL_t,
null=True,
on_delete=models.SET_NULL,
verbose_name="Choose Project"
)
project_name_work = models.ForeignKey(
GENERAL_t.project_name,
null=True,
verbose_name='Project_Name'
)

Answer 1

You don't need to do that, and a FK won't allow that. The FK field is just the ID of a row in another table, nothing more complex than that really.
When working with ForeignKey links like this it's a good idea to use strings so that you don't have to import the related model. The format of the string is '<appname.ModelName>
For example, I link an object to a (django) content type like this;
source_content_type = models.ForeignKey(
verbose_name=_('source content type'),
to='contenttypes.ContentType',
on_delete=models.CASCADE
)
So to link your EDVT model to a GENERAL_t you'd do;
class EDVT(models.Model):
general_t = models.ForeignKey(
to='Manin_matrix.GENERAL_t',
null=True,
verbose_name='general t'
)
Then if EDVT needs to be able to return a project_name you could do it as a property.
class EDVT(models.Model):
project_rel = models.ForeignKey(
to='Manin_matrix.GENERAL_t',
null=True,
verbose_name='Project_Name'
)
#property
def project_name(self):
return self.project_rel.project_name
Then you can access it either by EDVT.objects.first().project_name or if you didn't implement the property you can do EDVT.objects.first().general_t.project_name (or any other field on that model)