Question

我有一个模型，该模型是用于创建对象的模板

byte[] bb;
Bitmap bmp = this.screenshots.RemoveFromFront();
Stream stream = new MemoryStream();
EncoderParameters encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);
bmp.Save(stream, GetEncoder(ImageFormat.Jpeg), encoderParameters);
using (var compressStream = new MemoryStream())
using (var compressor = new DeflateStream(compressStream, CompressionMode.Compress))
{
       stream.CopyTo(compressor);
       compressor.Close();
       bb = compressStream.ToArray();
}

用于通过联赛模型从外部API创建对象的数据

League(models.Model):                                      
     league = models.IntegerField(primary_key=True)
     league_name =models.CharField(max_length=200)             
     country_code = models.ForeignKey("Country",null=True, on_delete=models.SET_NULL)                                       
     season = models.ForeignKey("Season", null=True,on_delete = models.SET_NULL, to_field = "season")
     season_start = models.DateField(null = True)
     season_end = models.DateField(null = True)
     league_logo = models.URLField(null = True)                   
     league_flag = models.URLField(null = True)
     standings = models.IntegerField(null=True)
     is_current = models.IntegerField(null=True)                  
     cover_standings = models.BooleanField(null=True)           
     cover_fixtures_events = models.BooleanField(null=True)     
     cover_fixtures_lineups = models.BooleanField(null=True)    
     cover_fixtures_statistics = models.BooleanField(null=True)                                                               
     cover_fixtures_players_statistics = models.BooleanField(null=True)                                                      
     cover_players = models.BooleanField(null=True)               
     cover_topScorers = models.BooleanField(null=True)          
     cover_predictions = models.BooleanField(null=True)
     cover_odds = models.BooleanField(null=True)                
     lastModified = models.DateTimeField(auto_now=True)

有时，对API的请求收到的响应中没有一些数据，而当我创建没有某些字段的对象时，会出错。这是我的问题，如何检查每个字段是否有数据。在python中以任何方式显示，除非else语句可以解决我的问题

Answer 1

您始终可以在模型字段中设置默认值。

例如：

league_name = models.CharField(max_length=200, defualt='none')

希望有帮助。

保存到数据库之前如何检查模型字段是否为空

1 个答案: