Expression to concatenate Django Postgres JSONField

concat_json_expression.py

from django.db.models.expressions import CombinedExpression, F, Value
from django.contrib.postgres.fields import JSONField


expression =  CombinedExpression(
    F('my_json_field'), 
    '||', 
    Value({'fizz': 'buzz'}, JSONField())
)

yes, it's just the Postgres jsonb concatenation operator (||).

Concatenating two objects generates an object containing the union of their keys, taking the second object's value when there are duplicate keys.