在模型order中添加字段discount字段，并给予初始值0

方法：

先在models.py中修改模型

添加

discount = models.DecimalField(max_digits=8,decimal_places=2, default=0)

然后，我们运行命令manage.py sqlall dish 来查看（dish是app名称）:

CREATE TABLE "dish_order" (    "id" integer NOT NULL PRIMARY KEY,    "datetime" datetime NOT NULL,    "customer_quantity" integer NOT NULL,    "table" varchar(128),    "seat" varchar(128),    "state" varchar(128) NOT NULL,    "discount" decimal NOT NULL,    "discount_detail" text,    "total_price" decimal,    "reserved" varchar(128));

 

执行如下语句

>>> from django.db import connection>>> cursor = connection.cursor()>>>cursor.execute('ALTER TABLE dish_order ADD COLUMN discount decimal DEFAULT 0')