samedi 29 novembre 2014

python - Django Models.py Database Design Feedback - Stack Overflow


Based on my previous question and feedback I received I have redesigned my Models and need some feedback before I run the "syncdb".


My concerns are mostly ForeignKeys and the one ManyToManyField in the Restaurant table. Should also the ManyTomany field have the through='' value and what the value should be?


Any feedback is appreciated!


Models


class Restaurant(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='name', blank=True)
address = models.CharField(max_length=100L, blank=True)
city_id = models.ForeignKey('City', related_name="restaurant_city")
location_id = models.ForeignKey('Location', related_name="restaurant_location")
hood_id = models.ForeignKey('Hood', null=True, blank=True, related_name="restaurant_hood")
listingrole_id = models.ForeignKey('Listingrole', related_name="restaurant_listingrole")
cuisine_types = models.ManyToManyField('Cuisinetype', null=True, blank=True, related_name="restaurant_cuisinetype")
class Meta:
db_table = 'restaurant'

class City(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='city')
state = models.CharField(max_length=50L, db_column='state', blank=True, null=True)
class Meta:
db_table = 'city'

class Cuisinetype(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='cuisine', blank=True) # Field name made lowercase.
class Meta:
db_table = 'cuisinetype'

class Location(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='location', blank=False, null=False)
city = models.ForeignKey('City', related_name="location_city")
class Meta:
db_table = 'location'

class Hood(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='hood')
city = models.ForeignKey('City', related_name='hood_city')
location = models.ForeignKey('Location', related_name='hood_location')
class Meta:
db_table = 'hood'

class Listingrole(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='listingrole', blank=True) # Field name made lowercase.
class Meta:
db_table = 'listingrole'
....



Having into account the concept and meaning of coisine_types you don't have to make the relationship using through keyword. You use it (mostly) when there is some information about the relation it self.


According Django documentation:



The most common use for this option is when you want to associate extra data with a many-to-many relationship.



See explanation here: Extra fields on many-to-many relationships



Based on my previous question and feedback I received I have redesigned my Models and need some feedback before I run the "syncdb".


My concerns are mostly ForeignKeys and the one ManyToManyField in the Restaurant table. Should also the ManyTomany field have the through='' value and what the value should be?


Any feedback is appreciated!


Models


class Restaurant(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='name', blank=True)
address = models.CharField(max_length=100L, blank=True)
city_id = models.ForeignKey('City', related_name="restaurant_city")
location_id = models.ForeignKey('Location', related_name="restaurant_location")
hood_id = models.ForeignKey('Hood', null=True, blank=True, related_name="restaurant_hood")
listingrole_id = models.ForeignKey('Listingrole', related_name="restaurant_listingrole")
cuisine_types = models.ManyToManyField('Cuisinetype', null=True, blank=True, related_name="restaurant_cuisinetype")
class Meta:
db_table = 'restaurant'

class City(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='city')
state = models.CharField(max_length=50L, db_column='state', blank=True, null=True)
class Meta:
db_table = 'city'

class Cuisinetype(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='cuisine', blank=True) # Field name made lowercase.
class Meta:
db_table = 'cuisinetype'

class Location(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='location', blank=False, null=False)
city = models.ForeignKey('City', related_name="location_city")
class Meta:
db_table = 'location'

class Hood(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='hood')
city = models.ForeignKey('City', related_name='hood_city')
location = models.ForeignKey('Location', related_name='hood_location')
class Meta:
db_table = 'hood'

class Listingrole(models.Model):
id = models.AutoField(primary_key=True, db_column='id')
name = models.CharField(max_length=50L, db_column='listingrole', blank=True) # Field name made lowercase.
class Meta:
db_table = 'listingrole'
....


Having into account the concept and meaning of coisine_types you don't have to make the relationship using through keyword. You use it (mostly) when there is some information about the relation it self.


According Django documentation:



The most common use for this option is when you want to associate extra data with a many-to-many relationship.



See explanation here: Extra fields on many-to-many relationships


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