from django.db import models
class School(models.Model):
 pass
class Message(models.Model):
 pass
class Teacher(models.Model):
 pass
 class Student(models.Model):
 GENDER_CHOICES = (
  ('male', "男"),
  ('female', "女"),
  ('secret', "保密")
 )

 name = models.CharField(max_length=40, blank=True, verbose_name="姓名")
 gender = models.CharField(max_length=6, choices=GENDER_CHOICES, default="secret", verbose_name="性別")
 age = models.IntegerField(default=0, verbose_name="年齡")
 rank = models.PositiveIntegerField(default=1, verbose_name="排名", unique=True)
 discount = models.DecimalField(max_digits=3, decimal_places=2, verbose_name="折扣", default=1.0)
 school = models.ForeignKey(to=School, verbose_name="學(xué)校", on_delete=models.CASCADE)
 message = models.OneToOneField(to=Message, verbose_name="信息", on_delete=models.CASCADE)
 teacher = models.ManyToManyField(verbose_name="老師", to=Teacher, blank=True)
 introduce = models.TextField(blank=True, verbose_name="介紹")
 grade = models.FloatField(default=0.0, verbose_name="成績")
 url = models.URLField(verbose_name="個人主頁", max_length=100)
 email = models.EmailField(verbose_name="郵箱")
 image = models.ImageField(upload_to='img/%Y/%m/%d/', verbose_name='上傳圖片', null=True)
 file = models.FileField(upload_to="file/%Y/%m/%d/", verbose_name="上傳文件", blank=True)
 is_deleted = models.BooleanField(verbose_name="已刪除", default=False, blank=True)
 time_added = models.DateTimeField(verbose_name="添加時間", auto_now_add=True, blank=True)
 def delete(self, using=None, keep_parents=False):
  self.is_deleted = True
  # some actions
  self.save()
 def save(self, force_insert=False, force_update=False, using=None,
    update_fields=None):
  # some actions
  self.name = self.name.capitalize() # 首字母大寫
  return super().save(force_insert=force_insert, force_update=force_update, using=using,
       update_fields=update_fields)
 def __repr__(self):
  return "UserProfile:{}".format(self.name)
 def __str__(self):
  return self.name
 class Meta:
  ordering = ['-time_added']
  verbose_name = "用戶信息"
  verbose_name_plural = verbose_name
  db_table = "student_info"

from django.db import models
from django.utils import timezone
class Message(models.Model):
add_date = models.DateTimeField(verbose_name='保存日期',default = timezone.now)
mod_date = models.DateTimeField(verbose_name='最后修改日期', auto_now = True)

student = Student.objects.create(name='zhangsan', gender='male')

obj, created = Person.objects.get_or_create(
 first_name='John',
 last_name='Lennon',
 defaults={'birthday': date(1940, 10, 9)},
)

try:
 obj = Person.objects.get(first_name='John', last_name='Lennon')
except Person.DoesNotExist:
 obj = Person(first_name='John', last_name='Lennon', birthday=date(1940, 10, 9))
 obj.save()

obj, created = Person.objects.update_or_create(
 first_name='John', last_name='Lennon',
 defaults={'first_name': 'Bob'},
)

defaults = {'first_name': 'Bob'}
try:
 obj = Person.objects.get(first_name='John', last_name='Lennon')
 for key, value in defaults.items():
  setattr(obj, key, value)
 obj.save()
except Person.DoesNotExist:
 new_values = {'first_name': 'John', 'last_name': 'Lennon'}
 new_values.update(defaults)
 obj = Person(**new_values)
 obj.save()

>>> john = Author.objects.create(name="John")
>>> paul = Author.objects.create(name="Paul")
>>> george = Author.objects.create(name="George")
>>> ringo = Author.objects.create(name="Ringo")
>>> entry.authors.add(john, paul, george, ringo)

all_entries = Entry.objects.all()

>>> entry = Entry.objects.get(pk=1)
>>> cheese_blog = Blog.objects.get(name="Cheddar Talk")

>>> entry = Entry.objects.filter(pk=1)[0]
>>> cheese_blog = Blog.objects.filter(name="Cheddar Talk")[0]

Entry.objects.filter(pub_date__year=2006)
Entry.objects.all().filter(pub_date__year=2006)
Entry.objects.filter(blog__name__year="zhangsan")

Entry.objects.filter(
...  headline__startswith='What'
... ).exclude(
...  pub_date__gte=datetime.date.today()
... ).filter(
...  pub_date__gte=datetime.date(2005, 1, 30)
... )

student = student.filter(Q(name__icontains=search) |
       Q(teacher__name__icontains=search) |
       Q(gender__icontains=search) |
       Q(url__icontains=search))

query = Q(name__icontains=search)
query = query | Q(teacher__name__icontains=search)
student = student.filter(query)