I am using CassandraDB in a flask project
I have created a User Model which has email as the primary_key.
class User(Model):
__table_name__ = 'user'
user_id = UUID(primary_key=True)
email = Text(max_length=120, primary_key=True)
first_name = Text()
last_name = Text()
python code:
user_data = {'email': 'john@example.com', "first_name":'John', "last_name":'Doe'}
user = User(**user_data)
user.save()
the Above code correctly creates the user as required
user_data = {'email': 'john@example.com', "first_name":'Johnny', "last_name":'Daves'}
user = User(**user_data)
user.save()
Now the above code updates the existing User 'john doe' to 'johnny daves'. what I was expecting to get was an error raised by cqlengine stating "user with email john@example.com already exists"
Why did it not raise the error? Am I doing something wrong?
I manage to figure out the answer, after going through the code I was able to notice that Model class has an property called _if_not_exists = False which if set will raise LWTException indicating that the object already exists in the database and you cannot create it.
class User(Model):
__table_name__ = 'user'
_if_not_exists = True
user_id = UUID(primary_key=True)
email = Text(max_length=120, primary_key=True)
first_name = Text()
last_name = Text()
as shown above setting _if_not_exists = True in the model solved my problem :)