AttributeError: module 'MySQLdb.constants.FIELD_TYPE' has no attribute 'JSON' while migrating in Django
__init__.py
# import pymysql
# pymysql.version_info = (1, 3, 13, "final", 0)
# pymysql.install_as_MySQLdb() 解決更新mysqlclient：
pip install mysqlclient==2.0.1
可支援jsonfield的django3和mysqlclient版本，此版本不在使用pymysql，
直接使用mysqlclient,并且注釋掉settings.py 中__init__.py pymysql引用，源碼無需修改：
Django==3.1.2 mysqlclient==2.0.1 amqp==1.4.9
anyjson==0.3.3
appdirs==1.4.4
asgiref==3.2.10
billiard==3.3.0.23
celery==3.1.26.post2
certifi==2020.6.20
chardet==3.0.4
click==7.1.2
click-didyoumean==0.0.3
click-repl==0.1.6
configparser==5.0.1
coreapi==2.3.3
coreschema==0.0.4
distlib==0.3.1
Django==3.1.2
django-celery==3.3.1
django-filter==2.4.0
django-mysql==3.9.0
djangorestframework==3.12.1
drf-extensions==0.6.0
fdfs-client-py==1.2.6
filelock==3.0.12
filetype==1.0.7
flower==0.9.5
humanize==3.0.1
idna==2.10
importlib-metadata==2.0.0
importlib-resources==3.0.0
install==1.3.4
itypes==1.2.0
Jinja2==2.11.2
jsonfield==3.1.0
jsonpath==0.82
kombu==3.0.37
MarkupSafe==1.1.1
minio==6.0.0
mutagen==1.45.1
mysqlclient==2.0.1
Pillow==8.0.1
prometheus-client==0.8.0
prompt-toolkit==3.0.8
psycopg2==2.8.6
PyMySQL==0.10.1
python-dateutil==2.8.1
pytz==2020.1
redis==2.10.6
requests==2.24.0
six==1.15.0
sqlparse==0.4.1
tornado==6.0.4
uritemplate==3.0.1
urllib3==1.25.10
vine==5.0.0
virtualenv==20.0.35
wcwidth==0.2.5
zipp==3.3.1 模型舉例：
def json_default():
return {} class JsonModels(models.Model):
names=models.CharField(max_length=50)
attrs =models.JSONField(default=json_default)
class Meta:
db_table='tbl_test_jsonfiled'
verbose_name="jsonfield測試"
傳參： 
空值測試：
mysql> select * from tbl_test_jsonfiled;
+----+-----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id | names | attrs |
+----+-----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 1 | testjson | {"id": 2067, "age": 28, "sex": "男", "addr": "河南省濟源市北海大道32号", "gold": 100, "name": "小黑", "grade": "天蠍座", "phone": "12345678915"} |
| 2 | 測試空 | {} |
+----+-----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
其次還可以設定sql null : class JsonModels(models.Model):
names=models.CharField(max_length=50)
attrs =models.JSONField(null=True)
class Meta:
db_table='tbl_test_jsonfiled'
verbose_name="jsonfield測試" mysql> select * from tbl_test_jsonfiled;
+----+-----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id | names | attrs |
+----+-----------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 1 | testjson | {"id": 2067, "age": 28, "sex": "男", "addr": "河南省濟源市北海大道32号", "gold": 100, "name": "小黑", "grade": "天蠍座", "phone": "12345678915"} |
| 2 | 測試空 | {} |
| 3 | yan | NULL
django 2.x支援JSONField問題： pip install mysqlclient==2.0.1 pip install django-mysql==3.9.0
pip install Django==2.2.17
注意事項：
1.注冊app django_mysql到settings應用裡面
2.使用方法： from django.db import models
from django_mysql.models import JSONField
class JsonModels(models.Model):
names=models.CharField(max_length=50)
attrs =JSONField(null=True)
class Meta:
db_table='tbl_jang2_jsonfiled'
verbose_name="jsonfield測試" 空值測試不傳則存為{}
mysql> select * from tbl_jang2_jsonfiled;
+----+-----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id | names | attrs |
+----+-----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 1 | jang2test | {} |
| 2 | jang2test | {"url": "http://127.0.0.1:7888/no/params?id=1001&name=WangXinRan&pwd=testapi", "json": null, "expect": null, "method": "get", "params": null, "headers": {"Content-Type": "application/x-www-form-urlencoded"}, "response_validation": null} |
+----+-----------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
此外JSONField還可以存入List,string curl --location --request POST 'http://127.0.0.1:8000/testjson/' \
--header 'Content-Type: application/json' \
--data-raw '
{
"names":"listtest",
"attrs":[1,2,3,"hello",{"hello":"testt"}]
}'
mysql> select * from tbl_jang2_jsonfiled;
+----+-----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id | names | attrs |
+----+-----------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 1 | jang2test | {} |
| 2 | jang2test | {"url": "http://127.0.0.1:7888/no/params?id=1001&name=WangXinRan&pwd=testapi", "json": null, "expect": null, "method": "get", "params": null, "headers": {"Content-Type": "application/x-www-form-urlencoded"}, "response_validation": null} |
| 3 | jang2test | {} |
| 4 | listtest | [1, 2, 3, "hello", {"hello": "testt"}] |
+----+-----------+---------------------------------------------------