想在模型essay中添加字段view_count粥帚，并給予初始值0
方法：
先在models.py中修改模型
添加
view_count=models.IntegerField(verbose_name='瀏覽次數(shù)',default=0)
然后驶拱，我們運(yùn)行命令manage.py sqlall core來(lái)查看，以下是其中一段:
CREATE TABLE "core_essay" (
"id" integer NOT NULL PRIMARY KEY,
"eType_id" integer NOT NULL REFERENCES "core_eassaytype" ("id"),
"title" varchar(25) NOT NULL,
"content" text NOT NULL,
"abstract" text NOT NULL,
"pub_date" datetime NOT NULL,
"view_count" integer NOT NULL
)
;
執(zhí)行如下語(yǔ)句
>>> from django.db import connection
>>> cursor = connection.cursor()
>>>cursor.execute('ALTER TABLE core_essay ADD COLUMN view_count integer DEFAULT 0')
<django.db.backends.sqlite3.base.SQLiteCursorWrapper object at 0x020C31C0>
