Django join where values not null
I have 3 Tabels in Django
class Transactions(models.Model):
public_key = models.ForeignKey(Keys, on_delete=models.CASCADE)
txid = models.CharField(max_length=30)
timestamp = models.DateTimeField()
hash = models.CharField(max_length=64)
block = models.IntegerField()
amount = models.IntegerField()
saldo = models.IntegerField()
fee = models.IntegerField()
fiat_CHF = models.FloatField(default=0)
fiat_USD = models.FloatField(default=0)
fiat_EUR = models.FloatField(default=0)
position = models.IntegerField(default=0)
class Price(models.Model):
date = models.DateTimeField()
price = models.FloatField()
fiat = models.ForeignKey(Currencies, on_delete=models.DO_NOTHING)
class PriceTextBackup(models.Model):
date = models.CharField(max_length=20)
price = models.FloatField()
fiat = models.ForeignKey(Currencies, on_delete=models.DO_NOTHING)
Now i want to 'join' transactions with price on the date, if it is null i want to check the text backup, if it is still null, i want it to be 0.
Is that possible? and how?
Edit
Could that be achived with a combination of data selection and data displaying?