听起来该annotate()
功能在 Django 1.8 中变得更加灵活。您可以将两个字段与一个Concat
表达式组合,然后用该表达式注释查询集。
# Tested with Django 1.9.2
import sys
import django
from django.apps import apps
from django.apps.config import AppConfig
from django.conf import settings
from django.db import connections, models, DEFAULT_DB_ALIAS
from django.db.models.base import ModelBase
from django.db.models.functions import Concat, Value
NAME = 'udjango'
def main():
setup()
class Person(models.Model):
first_name = models.CharField(max_length=30)
last_name = models.CharField(max_length=30)
syncdb(Person)
Person.objects.create(first_name='Jimmy', last_name='Jones')
Person.objects.create(first_name='Bob', last_name='Brown')
print(Person.objects.annotate(
full_name=Concat('first_name',
Value(' '),
'last_name')).values_list('id', 'full_name'))
# >>> [(1, u'Jimmy Jones'), (2, u'Bob Brown')]
def setup():
DB_FILE = NAME + '.db'
with open(DB_FILE, 'w'):
pass # wipe the database
settings.configure(
DEBUG=True,
DATABASES={
DEFAULT_DB_ALIAS: {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': DB_FILE}},
LOGGING={'version': 1,
'disable_existing_loggers': False,
'formatters': {
'debug': {
'format': '%(asctime)s[%(levelname)s]'
'%(name)s.%(funcName)s(): %(message)s',
'datefmt': '%Y-%m-%d %H:%M:%S'}},
'handlers': {
'console': {
'level': 'DEBUG',
'class': 'logging.StreamHandler',
'formatter': 'debug'}},
'root': {
'handlers': ['console'],
'level': 'WARN'},
'loggers': {
"django.db": {"level": "WARN"}}})
app_config = AppConfig(NAME, sys.modules['__main__'])
apps.populate([app_config])
django.setup()
original_new_func = ModelBase.__new__
@staticmethod
def patched_new(cls, name, bases, attrs):
if 'Meta' not in attrs:
class Meta:
app_label = NAME
attrs['Meta'] = Meta
return original_new_func(cls, name, bases, attrs)
ModelBase.__new__ = patched_new
def syncdb(model):
""" Standard syncdb expects models to be in reliable locations.
Based on https://github.com/django/django/blob/1.9.3
/django/core/management/commands/migrate.py#L285
"""
connection = connections[DEFAULT_DB_ALIAS]
with connection.schema_editor() as editor:
editor.create_model(model)
main()