Django Postgresql刪除列默認在遷移

例如我已經這種模式：

mydb=# \d model1 
           Table "public.model1" 
Column |   Type   |      Modifiers      
--------+-----------------------+----------------------------------------------------- 
id  | integer    | not null default nextval('model1_id_seq'::regclass) 
field1 | character varying(50) | not null 
field2 | character varying(10) | not null 
Indexes: 
    "model1_pkey" PRIMARY KEY, btree (id)

遷移sqlmigrate的輸出爲：：

class model1(models.Model): 
     field1 = models.CharField(max_length=50, default='My Default Value 1',db_column='field1') 
     field2 = models.CharField(max_length=10) 

     class Meta: 
      db_table = 'model1'

和PostgreSQL表而不默認生成

CREATE TABLE "model1" ("id" serial NOT NULL PRIMARY KEY, "field1" varchar(50) NOT NULL, "field2" varchar(10) NOT NULL); 
COMMIT;

但如果我修改模型中的默認值並運行makemigrations/migrate，然後我考慮sqlmigrations輸出genereates一個奇怪的DROP DEFAULT創建

ALTER TABLE "model1" ALTER COLUMN "field1" SET DEFAULT 'My Default Value 1 modified'; 
ALTER TABLE "model1" ALTER COLUMN "field1" DROP DEFAULT; 
COMMIT;

後有什麼我丟失或列的缺省值只是不支持？

來源

2017-02-21 Cristobal Vargas