我想在我的ClientUploads模型中添加created_at字段。它看起来像这样：
@python_2_unicode_compatible
class ClientUploads(models.Model):
client = models.OneToOneField(Client)
#created_at = models.DateTimeField(auto_now_add=True)
def generate_filename(self, filename):
name = "uploads/%s/%s" % (self.client.company, filename)
return name
file_upload = models.FileField(upload_to=generate_filename)
def __str__(self):
return self.client.company
class Meta:
verbose_name_plural = _("Client Uploads")
verbose_name = _("Client Upload")
但是当我添加created_at然后提交表单时，我得到的错误是该列不存在。我尝试重命名模型，并进行迁移以擦除旧模型并创建另一个模型，其中created_at从一开始就存在但我仍然遇到相同的错误。如何添加此字段？或者是否已经有这样的领域？无论我需要一个created_at字段，我都无法在不破坏表单的情况下找到它的添加方法。
答案 0 :(得分：0)
根据您发布的代码，您已将created_at字段注释掉。您需要取消注释该行（删除前面的using System;
using System.IO;
namespace ConsoleApplication2
{
class Program
{
static void Main(string[] args)
{
var fileContents = ReadFile();
Console.ReadLine(); // cause program to pause at the end
}
public static string ReadFile()
{
try
{
using (var streamReader = new StreamReader(
@"C:\MyTestFile.txt"))
{
var fileContents = streamReader.ReadToEnd();
Console.WriteLine("File was read successfully");
return fileContents;
}
}
catch (FileNotFoundException fileNotFoundException)
{
LogReadFileException(fileNotFoundException);
}
catch (DirectoryNotFoundException directoryNotFoundException)
{
LogReadFileException(directoryNotFoundException);
}
catch (IOException ioException)
{
LogReadFileException(ioException);
}
// If we get here, an exception occurred
Console.WriteLine("File could not be read successfully");
return string.Empty;
}
private static void LogReadFileException(Exception exception)
{
string logFilePath = @"C:\MyLogFile.txt";
using (var streamWriter = new StreamWriter(logFilePath,
append: true))
{
var errorMessage = "Exception occurred: " +
exception.Message;
streamWriter.WriteLine(errorMessage);
Console.WriteLine(errorMessage);
}
}
}
}
），然后运行#，然后manage.py makemigrations。
答案 1 :(得分：0)
删除数据库，然后运行makemigrations并migrate和createsuperuser，并从头开始重新输入数据。我试过冲洗，没有工作。 echo "" > dbfile也有效。