Domanda
Ho due modelli a Django per un gioco basato su mappa 2D:
class Block(models.Model):
type = models.IntegerField()
class ShopBuilding(models.Model):
house_blocks = models.ManyToManyField(Block)
street_blocks = models.ManyToManyField(Block)
river_blocks = models.ManyToManyField(Block)
decoration_blocks = models.ManyToManyField(Block)
npc_blocks = models.ManyToManyField(Block)
.
Ora voglio solo associare questi due modelli usando una tabella:
class ShopBlockAssoc(models.Model):
block = models.ForeignKey(Block)
shop = models.foreignKey(Shop)
.
Dopo aver impostato il campo through
nel modello ShopBuilding
, Django Yipled Multiple non riesce quando SyncDb, come
Error: One or more models did not validate:
tnew.shopbuilding: Accessor for m2m field 'house_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'house_blocks'.
tnew.shopbuilding: Accessor for m2m field 'house_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'house_blocks'.
tnew.shopbuilding: Accessor for m2m field 'house_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'house_blocks'.
tnew.shopbuilding: Accessor for m2m field 'house_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'house_blocks'.
tnew.shopbuilding: Accessor for m2m field 'street_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'street_blocks'.
tnew.shopbuilding: Accessor for m2m field 'street_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'street_blocks'.
tnew.shopbuilding: Accessor for m2m field 'street_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'street_blocks'.
tnew.shopbuilding: Accessor for m2m field 'street_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'street_blocks'.
tnew.shopbuilding: Accessor for m2m field 'river_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'river_blocks'.
tnew.shopbuilding: Accessor for m2m field 'river_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'river_blocks'.
tnew.shopbuilding: Accessor for m2m field 'river_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'river_blocks'.
tnew.shopbuilding: Accessor for m2m field 'river_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'river_blocks'.
tnew.shopbuilding: Accessor for m2m field 'decoration_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'decoration_blocks'.
tnew.shopbuilding: Accessor for m2m field 'decoration_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'decoration_blocks'.
tnew.shopbuilding: Accessor for m2m field 'decoration_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'decoration_blocks'.
tnew.shopbuilding: Accessor for m2m field 'decoration_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'decoration_blocks'.
tnew.shopbuilding: Accessor for m2m field 'npc_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'npc_blocks'.
tnew.shopbuilding: Accessor for m2m field 'npc_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'npc_blocks'.
tnew.shopbuilding: Accessor for m2m field 'npc_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'npc_blocks'.
tnew.shopbuilding: Accessor for m2m field 'npc_blocks' clashes with related m2m field 'Block.shopbuilding_set'. Add a related_name argument to the definition for 'npc_blocks'.
.
Se ho impostato il campo db_table
Django dice:
The model has two manually-defined m2m relations through the model, which is not permitted. Please consider using an extra field on your intermediary model instead.
.
Come potrei risolvere questo?Voglio davvero assicurarmi che quelle relazioni del negozio di negozi stiano utilizzando la condivisione dello stesso modello associato intermedio con lo stesso db_table
Soluzione
The problem is that on model Block
it tries to create backwards links. Django names those links based on Model, in your case for all ManyToMany it tries to create shopbuilding_set
and names collide. To avoid this add related_name
, for example:
class ShopBuilding(models.Model):
house_blocks = models.ManyToManyField(Block, related_name="shopbuilding_house_set")
street_blocks = models.ManyToManyField(Block, related_name="shopbuilding_street_set")
river_blocks = models.ManyToManyField(Block, related_name="shopbuilding_river_set")
decoration_blocks = models.ManyToManyField(Block, related_name="shopbuilding_decoration_set")
npc_blocks = models.ManyToManyField(Block, related_name="shopbuilding_npc_set")
Then you'll be able to access ShopBuilding
from Block
instance like this:
block.shopbuilding_npc_set.all()