有时候由于添加字段顺序不对，需要对table重建
1. 物理delete table
2.删除model上这个表
3. python manage.py makemigrations rowtable
执行makemigration - Delete model ParentSurvey
4.假装删除表，目的是让model与实际table一致
python manage.py migrate --fake rowtable
5.在model上添加表，并makemigrations
(py3.6env) lxg@lxg-opt:~/98receive/pystudy/generaldb$ python manage.py makemigrations rowtable
Migrations for ‘rowtable‘:
rowtable/migrations/0010_parentsurvey.py
- Create model ParentSurvey
6.migrate ，物理上添加表
(py3.6env) lxg@lxg-opt:~/98receive/pystudy/generaldb$ python manage.py migrate rowtable