自定义django管理命令：使用模型和crontab存在问题

我创建了自定义的django管理命令。我使用这个教程

例如，我的命令：

import os
from home.models import BuildTask

class Command(BaseCommand):
    def handle(self, *args, **options):

        tasks = BuildTask.objects.all()

        os.system("touch /Users/macbook/Desktop/Start.txt")

        if tasks:
            os.system("touch /Users/macbook/Desktop/TasksExist.txt")
        else:
            os.system("touch /Users/macbook/Desktop/TasksNotExist.txt")

        os.system("touch /Users/macbook/Desktop/End.txt")

使用终端运行此命令时：

python manage.py build_task

一切正常，我在Destop上有3个文件

但是当我使用crontab时

* * * * *  /usr/bin/python /Users/macbook/builder/manage.py build_task

我只是在桌面上得到一个文件（“Start.txt”）。很明显，脚本在线路上停止了作业

if tasks:

请帮帮我。有什么问题吗

更新：/var/mail/macbook:

 File "/Users/macbook/workspace/acodebuilder/home/management/commands/build_apk.py",    
     line 26, in handle
 if tasks:
 File "/Library/Python/2.7/site-packages/django/db/models/query.py", line 113, in 
     __nonzero__
 iter(self).next()
 File "/Library/Python/2.7/site-packages/django/db/models/query.py", line 107, in 
     _result_iter
 self._fill_cache()
 File "/Library/Python/2.7/site-packages/django/db/models/query.py", line 772, in 
     _fill_cache
 self._result_cache.append(self._iter.next())
 File "/Library/Python/2.7/site-packages/django/db/models/query.py", line 273, in 
     iterator
 for row in compiler.results_iter():
 File "/Library/Python/2.7/site-packages/django/db/models/sql/compiler.py", line 680, in
    results_iter
 for rows in self.execute_sql(MULTI):
 File "/Library/Python/2.7/site-packages/django/db/models/sql/compiler.py", line 735, in 
     execute_sql
 cursor.execute(sql, params)
 File "/Library/Python/2.7/site-packages/django/db/backends/util.py", line 34, in 
     execute
 return self.cursor.execute(sql, params)
 File "/Library/Python/2.7/site-packages/django/db/backends/sqlite3/base.py", line 234, 
    in execute
 return Database.Cursor.execute(self, query, params)

 django.db.utils.DatabaseError: no such table: home_buildtask

---

为什么“没有这样的表”

通过运行

mail

命令，您应该能够看到命令的错误输出（如果有）。或者，您可以将

&>~/Desktop/django command error.log

附加到crontab条目，cron作业的错误输出将保存到桌面上的

django command error.log

。

这是由SQLite db引起的问题，我们必须使用MySQL或PGSQL