Peewee 外键不是 integer

Question

I try to compare to integers but the ForeignKey Value isn't an integer:

class Player(Model):

    id = IntegerField(primary_key=True)
    first_name = CharField(max_length=32)

    class Meta:
        database = db
        db_table = "player"


class Club(Model):
    id = IntegerField(primary_key=True)
    owner = ForeignKeyField(Player, backref='owner')
    class Meta:
       database = db
       db_table = "club"

Now I try to compare the current session["id"] with the owner from the database:

club_data = Club.get(Club.id == id)
if session["id"] == club_data.owner:
    do_some_things()

The value club_data.owner isn't an integer. Did I make a mistake on the Database file?

When I try int(club_data.owner) , I get the following error message: int() argument must be a string, a bytes-like object or a number, not 'Player'

print(club_data.owner) is 0 and session["id"] is also 0

Where did I make a mistake?

Answer 1

You probably want if session["id"] == club_data.owner.id , since your second error suggests that club_data.owner has the type Player , not int . If it's a player you can get its id attribute to compare.

As a note, this:

print(club_data.owner) is 0 and session["id"] is also 0

Is not going to do what you think. print() will return None which is not 0 , so the comparison ( is ), while also throwing a warning will not ever evaluate to True.

Answer 2

Internally the foreign key is an integer. But Peewee automatically gets the Player object for you from that foreign key, so club_data.owner is that object. To get the ID, you need to access its .id attribute.

if session['id'] == club_data.owner.id:
    do_some_things()

Answer 3

The other answerers are on the right track, but traversing the foreign-key will result in an extra query --- which is unnecessary to just compare the ID:

club_data = Club.get(Club.id == id)
# Replace '.owner' with '.owner_id':
if session["id"] == club_data.owner_id:
    do_some_things()