在Peewee我有一個日期時間字段默認datetime.datetime.now（）。但插入時，服務器啓動需要花費時間。爲什麼

Question

當我插入一行時，該字段被填滿了服務器啓動的時間，而不是該行插入的時間。爲什麼會發生這種情況，解決方案是什麼？順便說一句，我正在使用SQLite。

class LOG(peewee.Model): 
    id = peewee.IntegerField(unique=True,primary_key=True) 
    timestamp = peewee.DateTimeField(default=datetime.datetime.now()) 
    log = peewee.CharField() 
    by = peewee.IntegerField(default=1) 
    class Meta: 
     database = database 


    LOG.create(log = _log , by = _by) 
    # above statement is called at say 3:00 pm and I started the server at 2:00 pm, then the row is inserted with timestamp of 2pm not 3pm. 

Answer 1

它走的是編譯時間（沒有測試）

class LOG(peewee.Model): 
    id = peewee.IntegerField(unique=True,primary_key=True) 
    timestamp = peewee.DateTimeField() 
    log = peewee.CharField() 
    by = peewee.IntegerField(default=1) 
    class Meta: 
     database = database 

    def save(self, *args, **kwargs): 
     self.modified = datetime.datetime.now() 
     return super(Something, self).save(*args, **kwargs) 

似乎這 is there an auto update option for DateTimeField in peewee like TimeStamp in MySQL?

複製（在服務器啓動的時間）

覆蓋的保存方法

Answer 2

當您的字段由Python解釋器加載時，它只會調用datetime.datetime.now()一次。所以你將永遠得到相同的價值。

Peewee支持使用可調用默認ARGS，所以而非調用 NOW（）只是傳遞中的作用：

timestamp = peewee.DateTimeField(default=datetime.datetime.now) 

Answer 3

應該這樣做。重寫保存方法

class myModel(Model): 

    name = CharField() 
    timestamp = DateTimeField() 

    def save(self, *args, **kwargs): 
     self.timestamp = datetime.datetime.now() 
     super(myModel, self).save(*args, **kwargs) 

工作正常後，此修復