For models with several foreignkeys to the same table, like this :
class File(models.Model):
Name = models.CharField(maxlength=200,null=False, blank=False, unique=True)
Storage = models.CharField(maxlength=200, null=True, blank=True)
def __repr__(self):
return self.Name
class Job(models.Model):
Name = models.CharField(maxlength=200)
Script_FK = models.ForeignKey(File,related_name='Script', verbose_name="The script file",null=True, blank=True)
JobLog_FK = models.ForeignKey(File,related_name='JobLog', verbose_name="The log file",null=True, blank=True)
def __repr__(self):
return self.Name
class Header(models.Model):
FULL_PATH_FITS = models.CharField(maxlength=200, null=False, blank=False, unique=True)
Fits_File_FK = models.ForeignKey(File, related_name='Fits_File_FK', verbose_name="The related File",null=True, blank=True)
def __repr__(self):
return str(int(self.FULL_PATH_FITS))
When we launch python manage.py syncdb" with an empty postgres db, some foreignkeys are missing :
=> \d process_job
Table "public.process_job"
Column | Type | Modifiers
--------------+------------------------+----------------------------------------------------------
id | integer | not null default nextval('process_job_id_seq'::regclass)
Name | character varying(200) | not null
Script_FK_id | integer |
JobLog_FK_id | integer |
Indexes:
"process_job_pkey" PRIMARY KEY, btree (id)
Foreign-key constraints:
"JobLog_FK_id_referencing_process_file_id" FOREIGN KEY ("JobLog_FK_id") REFERENCES process_file(id)
"Script_FK_id_referencing_process_file_id" FOREIGN KEY ("Script_FK_id") REFERENCES process_file(id)
=> \d process_header
Table "public.process_header"
Column | Type | Modifiers
--------------------+------------------------+-------------------------------------------------------------
id | integer | not null default nextval('process_header_id_seq'::regclass)
FULL_PATH_FITS | character varying(200) | not null
Fits_File_FK_id | integer |
Indexes:
"process_header_pkey" PRIMARY KEY, btree (id)
"process_header_FULL_PATH_FITS_key" UNIQUE, btree ("FULL_PATH_FITS")
I think the problem start with the update of the dictionnary "pending_references" in django/core/management.py :
(In the function syncdb()):
449 sql, references = _get_sql_model_create(model, seen_models)
450 seen_models.add(model)
451 created_models.add(model)
452 pending_references.update(references) #===============> Problem...
453 sql.extend(_get_sql_for_pending_references(model, pending_references))
The update function overwrites the previous references to the file table with the new ones.
In order to keep the previous foreignkeys, I've written the folowing function to replace the update dictionnary function :
def update_dict(dict_input = {},dict_update = {}):
"New update function which keep the previous references."
dict_output = dict_input
try :
for k_update, v_update in dict_update.items() :
try :
value_to_update = dict_input[k_update]
value_output = value_to_update + v_update
dict_output[k_update] = value_output
except :
dict_output[k_update] = v_update
except :
dict_output.update(dict_update)
return dict_output
and call it in syncdb():
pending_references = update_dict(pending_references,references)
The same error can be found in get_sql_create(app).
Now, in the db, we have :
\d process_header Table "public.process_header" Column | Type | Modifiers
--------------------+------------------------+-------------------------------------------------------------
id | integer | not null default nextval('process_header_id_seq'::regclass)
FULL_PATH_FITS | character varying(200) | not null
Fits_File_FK_id | integer |
Indexes:
"process_header_pkey" PRIMARY KEY, btree (id)
"process_header_FULL_PATH_FITS_key" UNIQUE, btree ("FULL_PATH_FITS")
Foreign-key constraints:
"Fits_File_FK_id_referencing_process_file_id" FOREIGN KEY ("Fits_File_FK_id") REFERENCES process_file(id)
\d process_job Table "public.process_job" Column | Type | Modifiers
--------------+------------------------+----------------------------------------------------------
id | integer | not null default nextval('process_job_id_seq'::regclass)
Name | character varying(200) | not null
Script_FK_id | integer |
JobLog_FK_id | integer |
Indexes:
"process_job_pkey" PRIMARY KEY, btree (id)
Foreign-key constraints:
"JobLog_FK_id_referencing_process_file_id" FOREIGN KEY ("JobLog_FK_id") REFERENCES process_file(id)
"Script_FK_id_referencing_process_file_id" FOREIGN KEY ("Script_FK_id") REFERENCES process_file(id)
