Django\u5f00\u53d1\u8fc7\u7a0b\u4e2d\u5bf9\u8868(model)\u7684\u589e\u5220\u6539\u67e5\u662f\u6700\u5e38\u7528\u7684\u529f\u80fd\u4e4b\u4e00\uff0c\u672c\u6587\u4ecb\u7ecd\u7b14\u8005\u5728\u4f7f\u7528model \u64cd\u4f5c\u8fc7\u7a0b\u4e2d\u9047\u5230\u7684\u4e00\u4e9b\u64cd\u4f5c\u3002<\/p>\n
\u5047\u5982\u6211\u4eec\u7684\u8868\u7ed3\u6784\u662f\u8fd9\u6837\u7684<\/p>\n
class User(models.Model):\n username = models.CharField(max_length=255, unique=True, verbose_name='\u7528\u6237\u540d')\n is_active = models.BooleanField(default=False, verbose_name='\u6fc0\u6d3b\u72b6\u6001')<\/code><\/pre>\n\u90a3\u4e48\u6211\u4eec\u4fee\u6539\u7528\u6237\u540d\u548c\u72b6\u6001\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u4e24\u79cd\u65b9\u6cd5\uff1a<\/p>\n
\u65b9\u6cd5\u4e00\uff1a<\/p>\n
User.objects.filter(id=1).update(username='nick',is_active=True)<\/code><\/pre>\n\u65b9\u6cd5\u4e8c\uff1a<\/p>\n
_t = User.objects.get(id=1)\n_t.username='nick'\n_t.is_active=True\n_t.save()<\/code><\/pre>\n\u65b9\u6cd5\u4e00\u9002\u5408\u66f4\u65b0\u4e00\u6279\u6570\u636e\uff0c\u7c7b\u4f3c\u4e8emysql\u8bed\u53e5update user set username='nick' where id = 1<\/code><\/p>\n\u65b9\u6cd5\u4e8c\u9002\u5408\u66f4\u65b0\u4e00\u6761\u6570\u636e\uff0c\u4e5f\u53ea\u80fd\u66f4\u65b0\u4e00\u6761\u6570\u636e\uff0c\u5f53\u53ea\u6709\u4e00\u6761\u6570\u636e\u66f4\u65b0\u65f6\u63a8\u8350\u4f7f\u7528\u6b64\u65b9\u6cd5\uff0c\u53e6\u5916\u6b64\u65b9\u6cd5\u8fd8\u6709\u4e00\u4e2a\u597d\u5904\uff0c\u6211\u4eec\u63a5\u7740\u5f80\u4e0b\u770b<\/p>\n
\u5177\u6709auto_now\u5c5e\u6027\u5b57\u6bb5\u7684\u66f4\u65b0<\/h1>\n
\u6211\u4eec\u901a\u5e38\u4f1a\u7ed9\u8868\u6dfb\u52a0\u4e09\u4e2a\u9ed8\u8ba4\u5b57\u6bb5<\/p>\n
\n- \u81ea\u589eID\uff0c\u8fd9\u4e2adjango\u5df2\u7ecf\u9ed8\u8ba4\u52a0\u4e86\uff0c\u5c31\u50cf\u4e0a\u8fb9\u7684\u5efa\u8868\u8bed\u53e5\uff0c\u867d\u7136\u53ea\u5199\u4e86username\u548cis_active\u4e24\u4e2a\u5b57\u6bb5\uff0c\u4f46\u8868\u5efa\u597d\u540e\u4e5f\u4f1a\u6709\u4e00\u4e2a\u9ed8\u8ba4\u7684\u81ea\u589eid\u5b57\u6bb5<\/li>\n
- \u521b\u5efa\u65f6\u95f4\uff0c\u7528\u6765\u6807\u8bc6\u8fd9\u6761\u8bb0\u5f55\u7684\u521b\u5efa\u65f6\u95f4\uff0c\u5177\u6709
auto_now_add<\/code>\u5c5e\u6027\uff0c\u521b\u5efa\u8bb0\u5f55\u65f6\u4f1a\u81ea\u52a8\u586b\u5145\u5f53\u524d\u65f6\u95f4\u5230\u6b64\u5b57\u6bb5<\/li>\n- \u4fee\u6539\u65f6\u95f4\uff0c\u7528\u6765\u6807\u8bc6\u8fd9\u6761\u8bb0\u5f55\u6700\u540e\u4e00\u6b21\u7684\u4fee\u6539\u65f6\u95f4\uff0c\u5177\u6709
auto_now<\/code>\u5c5e\u6027\uff0c\u5f53\u8bb0\u5f55\u53d1\u751f\u53d8\u5316\u65f6\u586b\u5145\u5f53\u524d\u65f6\u95f4\u5230\u6b64\u5b57\u6bb5<\/li>\n<\/ul>\n\u5c31\u50cf\u4e0b\u8fb9\u8fd9\u6837\u7684\u8868\u7ed3\u6784<\/p>\n
class User(models.Model):\n create_time = models.DateTimeField(auto_now_add=True, verbose_name='\u521b\u5efa\u65f6\u95f4')\n update_time = models.DateTimeField(auto_now=True, verbose_name='\u66f4\u65b0\u65f6\u95f4')\n username = models.CharField(max_length=255, unique=True, verbose_name='\u7528\u6237\u540d')\n is_active = models.BooleanField(default=False, verbose_name='\u6fc0\u6d3b\u72b6\u6001')<\/code><\/pre>\n\u5f53\u8868\u6709\u5b57\u6bb5\u5177\u6709auto_now<\/code>\u5c5e\u6027\u4e14\u4f60\u5e0c\u671b\u4ed6\u80fd\u81ea\u52a8\u66f4\u65b0\u65f6\uff0c\u5fc5\u987b\u4f7f\u7528\u4e0a\u8fb9\u65b9\u6cd5\u4e8c\u7684\u66f4\u65b0\uff0c\u4e0d\u7136auto_now\u5b57\u6bb5\u4e0d\u4f1a\u66f4\u65b0<\/strong>\uff0c\u4e5f\u5c31\u662f\uff1a<\/p>\n_t = User.objects.get(id=1)\n_t.username='nick'\n_t.is_active=True\n_t.save()<\/code><\/pre>\njson\/dict\u7c7b\u578b\u6570\u636e\u66f4\u65b0\u5b57\u6bb5<\/h1>\n
\u76ee\u524d\u4e3b\u6d41\u7684web\u5f00\u653e\u65b9\u5f0f\u90fd\u8bb2\u7a76\u524d\u540e\u7aef\u5206\u79bb\uff0c\u5206\u79bb\u4e4b\u540e\u524d\u540e\u7aef\u4ea4\u4e92\u7684\u6570\u636e\u683c\u5f0f\u5927\u90fd\u7528\u901a\u7528\u7684json\u578b\uff0c\u90a3\u4e48\u5982\u4f55\u7528\u6700\u5c11\u7684\u4ee3\u7801\u65b9\u4fbf\u7684\u66f4\u65b0json\u683c\u5f0f\u6570\u636e\u5230\u6570\u636e\u5e93\u5462\uff1f\u540c\u6837\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u4e24\u79cd\u65b9\u6cd5\uff1a<\/p>\n
\u65b9\u6cd5\u4e00\uff1a<\/p>\n
data = {'username':'nick','is_active':'0'}\nUser.objects.filter(id=1).update(**data)<\/code><\/pre>\n\n- \u540c\u6837\u8fd9\u79cd\u65b9\u6cd5\u4e0d\u80fd\u81ea\u52a8\u66f4\u65b0\u5177\u6709
auto_now<\/code>\u5c5e\u6027\u5b57\u6bb5\u7684\u503c<\/li>\n- \u901a\u5e38\u6211\u4eec\u518d\u53d8\u91cf\u524d\u52a0\u4e00\u4e2a\u661f\u53f7(*)\u8868\u793a\u8fd9\u4e2a\u53d8\u91cf\u662f\u5143\u7ec4\/\u5217\u8868\uff0c\u52a0\u4e24\u4e2a\u661f\u53f7\u8868\u793a\u8fd9\u4e2a\u53c2\u6570\u662f\u5b57\u5178<\/li>\n<\/ul>\n
\u65b9\u6cd5\u4e8c\uff1a<\/p>\n
data = {'username':'nick','is_active':'0'}\n_t = User.objects.get(id=1)\n_t.__dict__.update(**data)\n_t.save()<\/code><\/pre>\n\n- \u65b9\u6cd5\u4e8c\u548c\u65b9\u6cd5\u4e00\u540c\u6837\u65e0\u6cd5\u81ea\u52a8\u66f4\u65b0
auto_now<\/code>\u5b57\u6bb5\u7684\u503c<\/li>\n- \u6ce8\u610f\u8fd9\u91cc\u4f7f\u7528\u5230\u4e86\u4e00\u4e2a
**dict**<\/code>\u65b9\u6cd5<\/li>\n<\/ul>\n\u65b9\u6cd5\u4e09\uff1a<\/p>\n
_t = User.objects.get(id=1)\n_t.role=Role.objects.get(id=3)\n_t.save()<\/code><\/pre>\nForeignKey\u5b57\u6bb5\u66f4\u65b0<\/h1>\n
\u5047\u5982\u6211\u4eec\u7684\u8868\u4e2d\u6709Foreignkey\u5916\u952e\u65f6\uff0c\u8be5\u5982\u4f55\u66f4\u65b0\u5462\uff1f<\/p>\n
class User(models.Model):\n create_time = models.DateTimeField(auto_now_add=True, verbose_name='\u521b\u5efa\u65f6\u95f4')\n update_time = models.DateTimeField(auto_now=True, verbose_name='\u66f4\u65b0\u65f6\u95f4')\n username = models.CharField(max_length=255, unique=True, verbose_name='\u7528\u6237\u540d')\n is_active = models.BooleanField(default=False, verbose_name='\u6fc0\u6d3b\u72b6\u6001')\n role = models.ForeignKey(Role, on_delete=models.CASCADE, null=True, verbose_name='\u89d2\u8272')<\/code><\/pre>\n\u65b9\u6cd5\u4e00\uff1a<\/p>\n
User.objects.filter(id=1).update(role=2)<\/code><\/pre>\n\n- \u6700\u7b80\u5355\u7684\u65b9\u6cd5\uff0c\u76f4\u63a5\u8ba9\u7ed9role\u5b57\u6bb5\u8bbe\u7f6e\u4e3a\u4e00\u4e2aid\u5373\u53ef<\/li>\n
- \u5f53\u7136\u4e5f\u53ef\u4ee5\u7528dict\u4f5c\u4e3a\u53c2\u6570\u66f4\u65b0\uff1a<\/li>\n<\/ul>\n
User.objects.filter(id=1).update(**{'username':'nick','role':3})<\/code><\/pre>\n\u65b9\u6cd5\u4e8c\uff1a<\/p>\n
_role = Role.objects.get(id=2)\nUser.objects.filter(id=1).update(role=_role)<\/code><\/pre>\n\n- \u4e5f\u53ef\u4ee5\u8d4b\u503c\u4e00\u4e2a\u5b9e\u4f8b\u7ed9role<\/li>\n
- \u5f53\u7136\u4e5f\u53ef\u4ee5\u7528dict\u4f5c\u4e3a\u53c2\u6570\u66f4\u65b0\uff1a<\/li>\n<\/ul>\n
_role = Role.objects.get(id=1)\nUser.objects.filter(id=1).update(**{'username':'nick','role':_role})<\/code><\/pre>\n\u65b9\u6cd5\u4e09\uff1a<\/p>\n
_t = User.objects.get(id=1)\n_t.role=Role.objects.get(id=3)\n_t.save()<\/code><\/pre>\n\n- \u6ce8\u610f\uff1a\u8fd9\u91cc\u7684role\u5fc5\u987b\u8d4b\u503c\u4e3a\u4e00\u4e2a\u5bf9\u8c61\uff0c\u4e0d\u80fd\u5199id<\/strong>\uff0c\u4e0d\u7136\u4f1a\u62a5\u9519
"User.role" must be a "Role" instance<\/code><\/li>\n- \u5f53\u4f7f\u7528dict\u4f5c\u4e3a\u53c2\u6570\u66f4\u65b0\u65f6\u53c8\u6709\u4e00\u70b9\u4e0d\u540c\uff0c\u5982\u4e0b\u4ee3\u7801\uff1a<\/li>\n<\/ul>\n
_t = User.objects.get(id=1)\n_t.__dict__.update(**{'username':'nick','role_id':2})\n_t.save()<\/code><\/pre>\n\n- Foreignkey\u5916\u952e\u5fc5\u987b\u52a0\u4e0a
_id<\/code><\/strong>\uff0c\u4f8b\u5982\uff1a{'role_id':3}<\/li>\n- role_id\u540e\u8fb9\u5fc5\u987b\u8ddf\u4e00\u4e2aid\uff08int\u6216str\u7c7b\u578b\u90fd\u53ef\uff09\uff0c\u4e0d\u80fd\u8ddfrole\u5b9e\u4f8b<\/li>\n<\/ul>\n
ManyToManyField\u5b57\u6bb5\u66f4\u65b0<\/h1>\n
\u5047\u5982\u6211\u4eec\u7684\u8868\u4e2d\u6709ManyToManyField\u5b57\u6bb5\u65f6\u66f4\u65b0\u53c8\u6709\u4ec0\u4e48\u5f71\u54cd\u5462\uff1f<\/p>\n
class User(models.Model):\n create_time = models.DateTimeField(auto_now_add=True, verbose_name='\u521b\u5efa\u65f6\u95f4')\n update_time = models.DateTimeField(auto_now=True, verbose_name='\u66f4\u65b0\u65f6\u95f4')\n username = models.CharField(max_length=255, unique=True, verbose_name='\u7528\u6237\u540d')\n is_active = models.BooleanField(default=False, verbose_name='\u6fc0\u6d3b\u72b6\u6001')\n role = models.ForeignKey(Role, on_delete=models.CASCADE, null=True, verbose_name='\u89d2\u8272')\n groups = models.ManyToManyField(Group, null=True, verbose_name='\u7ec4')<\/code><\/pre>\nm2m\u66f4\u65b0\uff1am2m\u5b57\u6bb5\u6ca1\u6709\u76f4\u63a5\u66f4\u65b0\u7684\u65b9\u6cd5\uff0c\u53ea\u80fd\u901a\u8fc7\u6e05\u7a7a\u518d\u6dfb\u52a0\u7684\u65b9\u6cd5\u66f4\u65b0\u4e86<\/p>\n
_t = User.objects.get(id=1)\n_t.groups.clear()\n_t.groups.add(*[1,3,5])\n_t.save()<\/code><\/pre>\n\n- \n
add()<\/code>\uff1am2m\u5b57\u6bb5\u6dfb\u52a0\u4e00\u4e2a\u503c\uff0c\u5f53\u6709\u591a\u4e2a\u503c\u7684\u65f6\u5019\u53ef\u7528\u5217\u8868\uff0c\u53c2\u7167\u4e0a\u8fb9\u4f8b\u5b50<\/p>\n<\/li>\n- \n
\n- _t.groups.add(2)<\/li>\n
- _t.groups.add(Group.objects.get(id=2))<\/li>\n<\/ul>\n<\/li>\n
- \n
remove()<\/code>\uff1am2m\u5b57\u6bb5\u79fb\u9664\u4e00\u4e2a\u503c\uff0c\uff0c\u5f53\u6709\u591a\u4e2a\u503c\u7684\u65f6\u5019\u53ef\u7528\u5217\u8868\uff0c\u53c2\u7167\u4e0a\u8fb9\u4f8b\u5b50<\/p>\n<\/li>\n- \n
\n- _t.groups.remove(2)<\/li>\n
- _t.groups.remove(Group.objects.get(id=2))<\/li>\n<\/ul>\n<\/li>\n
- \n
clear()<\/code>\uff1a\u6e05\u7a7am2m\u5b57\u6bb5\u7684\u503c<\/p>\n<\/li>\n<\/ul>\nDjango model select\u7684\u5404\u79cd\u7528\u6cd5\u8be6\u89e3<\/h2>\n\u57fa\u672c\u64cd\u4f5c<\/h1>\n# \u83b7\u53d6\u6240\u6709\u6570\u636e\uff0c\u5bf9\u5e94SQL\uff1aselect * from User\nUser.objects.all()\n\n# \u5339\u914d\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name = '\u8fd0\u7ef4\u5496\u5561\u5427'\nUser.objects.filter(name='\u8fd0\u7ef4\u5496\u5561\u5427')\n\n# \u4e0d\u5339\u914d\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name != '\u8fd0\u7ef4\u5496\u5561\u5427'\nUser.objects.exclude(name='\u8fd0\u7ef4\u5496\u5561\u5427')\n\n# \u83b7\u53d6\u5355\u6761\u6570\u636e\uff08\u6709\u4e14\u4ec5\u6709\u4e00\u6761\uff0cid\u552f\u4e00\uff09\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where id = 724\nUser.objects.get(id=123)<\/code><\/pre>\n\u5e38\u7528\u64cd\u4f5c<\/h1>\n# \u83b7\u53d6\u603b\u6570\uff0c\u5bf9\u5e94SQL\uff1aselect count(1) from User\nUser.objects.count()\n\n# \u83b7\u53d6\u603b\u6570\uff0c\u5bf9\u5e94SQL\uff1aselect count(1) from User where name = '\u8fd0\u7ef4\u5496\u5561\u5427'\nUser.objects.filter(name='\u8fd0\u7ef4\u5496\u5561\u5427').count()\n\n# \u5927\u4e8e\uff0c>\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where id > 724\nUser.objects.filter(id__gt=724)\n\n# \u5927\u4e8e\u7b49\u4e8e\uff0c>=\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where id >= 724\nUser.objects.filter(id__gte=724)\n\n# \u5c0f\u4e8e\uff0c<\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where id < 724\nUser.objects.filter(id__lt=724)\n\n# \u5c0f\u4e8e\u7b49\u4e8e\uff0c<=\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where id <= 724\nUser.objects.filter(id__lte=724)\n\n# \u540c\u65f6\u5927\u4e8e\u548c\u5c0f\u4e8e\uff0c 1 < id < 10\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where id > 1 and id < 10\nUser.objects.filter(id__gt=1, id__lt=10)\n\n# \u5305\u542b\uff0cin\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where id in (11,22,33)\nUser.objects.filter(id__in=[11, 22, 33])\n\n# \u4e0d\u5305\u542b\uff0cnot in\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where id not in (11,22,33)\nUser.objects.exclude(id__in=[11, 22, 33])\n\n# \u4e3a\u7a7a\uff1aisnull=True\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where pub_date is null\nUser.objects.filter(pub_date__isnull=True)\n\n# \u4e0d\u4e3a\u7a7a\uff1aisnull=False\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where pub_date is not null\nUser.objects.filter(pub_date__isnull=True)\n\n# \u5339\u914d\uff0clike\uff0c\u5927\u5c0f\u5199\u654f\u611f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name like '%sre%'\uff0cSQL\u4e2d\u5927\u5c0f\u5199\u4e0d\u654f\u611f\nUser.objects.filter(name__contains="sre")\n\n# \u5339\u914d\uff0clike\uff0c\u5927\u5c0f\u5199\u4e0d\u654f\u611f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name like '%sre%'\uff0cSQL\u4e2d\u5927\u5c0f\u5199\u4e0d\u654f\u611f\nUser.objects.filter(name__icontains="sre")\n\n# \u4e0d\u5339\u914d\uff0c\u5927\u5c0f\u5199\u654f\u611f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name not like '%sre%'\uff0cSQL\u4e2d\u5927\u5c0f\u5199\u4e0d\u654f\u611f\nUser.objects.exclude(name__contains="sre")\n\n# \u4e0d\u5339\u914d\uff0c\u5927\u5c0f\u5199\u4e0d\u654f\u611f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name not like '%sre%'\uff0cSQL\u4e2d\u5927\u5c0f\u5199\u4e0d\u654f\u611f\nUser.objects.exclude(name__icontains="sre")\n\n# \u8303\u56f4\uff0cbetween and\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where id between 3 and 8\nUser.objects.filter(id__range=[3, 8])\n\n# \u4ee5\u4ec0\u4e48\u5f00\u5934\uff0c\u5927\u5c0f\u5199\u654f\u611f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name like 'sh%'\uff0cSQL\u4e2d\u5927\u5c0f\u5199\u4e0d\u654f\u611f\nUser.objects.filter(name__startswith='sre')\n\n# \u4ee5\u4ec0\u4e48\u5f00\u5934\uff0c\u5927\u5c0f\u5199\u4e0d\u654f\u611f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name like 'sh%'\uff0cSQL\u4e2d\u5927\u5c0f\u5199\u4e0d\u654f\u611f\nUser.objects.filter(name__istartswith='sre')\n\n# \u4ee5\u4ec0\u4e48\u7ed3\u5c3e\uff0c\u5927\u5c0f\u5199\u654f\u611f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name like '%sre'\uff0cSQL\u4e2d\u5927\u5c0f\u5199\u4e0d\u654f\u611f\nUser.objects.filter(name__endswith='sre')\n\n# \u4ee5\u4ec0\u4e48\u7ed3\u5c3e\uff0c\u5927\u5c0f\u5199\u4e0d\u654f\u611f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name like '%sre'\uff0cSQL\u4e2d\u5927\u5c0f\u5199\u4e0d\u654f\u611f\nUser.objects.filter(name__iendswith='sre')\n\n# \u6392\u5e8f\uff0corder by\uff0c\u6b63\u5e8f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name = '\u8fd0\u7ef4\u5496\u5561\u5427' order by id\nUser.objects.filter(name='\u8fd0\u7ef4\u5496\u5561\u5427').order_by('id')\n\n# \u591a\u7ea7\u6392\u5e8f\uff0corder by\uff0c\u5148\u6309name\u8fdb\u884c\u6b63\u5e8f\u6392\u5217\uff0c\u5982\u679cname\u4e00\u81f4\u5219\u518d\u6309\u7167id\u5012\u53d9\u6392\u5217\nUser.objects.filter(name='\u8fd0\u7ef4\u5496\u5561\u5427').order_by('name','-id')\n\n# \u6392\u5e8f\uff0corder by\uff0c\u5012\u5e8f\uff0c\u5bf9\u5e94SQL\uff1aselect * from User where name = '\u8fd0\u7ef4\u5496\u5561\u5427' order by id desc\nUser.objects.filter(name='\u8fd0\u7ef4\u5496\u5561\u5427').order_by('-id')<\/code><\/pre>\n\u8fdb\u9636\u64cd\u4f5c<\/h1>\n# limit\uff0c\u5bf9\u5e94SQL\uff1aselect * from User limit 3;\nUser.objects.all()[:3]\n\n# limit\uff0c\u53d6\u7b2c\u4e09\u6761\u4ee5\u540e\u7684\u6570\u636e\uff0c\u6ca1\u6709\u5bf9\u5e94\u7684SQL\uff0c\u7c7b\u4f3c\u7684\u5982\uff1aselect * from User limit 3,10000000\uff0c\u4ece\u7b2c3\u6761\u5f00\u59cb\u53d6\u6570\u636e\uff0c\u53d610000000\u6761\uff0810000000\u5927\u4e8e\u8868\u4e2d\u6570\u636e\u6761\u6570\uff09\nUser.objects.all()[3:]\n\n# offset\uff0c\u53d6\u51fa\u7ed3\u679c\u7684\u7b2c10-20\u6761\u6570\u636e\uff08\u4e0d\u5305\u542b10\uff0c\u5305\u542b20\uff09,\u4e5f\u6ca1\u6709\u5bf9\u5e94SQL\uff0c\u53c2\u8003\u4e0a\u8fb9\u7684SQL\u5199\u6cd5\nUser.objects.all()[10:20]\n\n# \u5206\u7ec4\uff0cgroup by\uff0c\u5bf9\u5e94SQL\uff1aselect username,count(1) from User group by username;\nfrom django.db.models import Count\nUser.objects.values_list('username').annotate(Count('id'))\n\n# \u53bb\u91cddistinct\uff0c\u5bf9\u5e94SQL\uff1aselect distinct(username) from User\nUser.objects.values('username').distinct().count()\n\n# filter\u591a\u5217\u3001\u67e5\u8be2\u591a\u5217\uff0c\u5bf9\u5e94SQL\uff1aselect username,fullname from accounts_user\nUser.objects.values_list('username', 'fullname')\n\n# filter\u5355\u5217\u3001\u67e5\u8be2\u5355\u5217\uff0c\u6b63\u5e38values_list\u7ed9\u51fa\u7684\u7ed3\u679c\u662f\u4e2a\u5217\u8868\uff0c\u91cc\u8fb9\u91cc\u8fb9\u7684\u6bcf\u6761\u6570\u636e\u5bf9\u5e94\u4e00\u4e2a\u5143\u7ec4\uff0c\u5f53\u53ea\u67e5\u8be2\u4e00\u5217\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528flat\u6807\u7b7e\u53bb\u6389\u5143\u7ec4\uff0c\u5c06\u6bcf\u6761\u6570\u636e\u7684\u7ed3\u679c\u4ee5\u5b57\u7b26\u4e32\u7684\u5f62\u5f0f\u5b58\u50a8\u5728\u5217\u8868\u4e2d\uff0c\u4ece\u800c\u907f\u514d\u89e3\u6790\u5143\u7ec4\u7684\u9ebb\u70e6\nUser.objects.values_list('username', flat=True)\n\n# int\u5b57\u6bb5\u53d6\u6700\u5927\u503c\u3001\u6700\u5c0f\u503c\u3001\u7efc\u5408\u3001\u5e73\u5747\u6570\nfrom django.db.models import Sum,Count,Max,Min,Avg\n\nUser.objects.aggregate(Count(\u2018id\u2019))\nUser.objects.aggregate(Sum(\u2018age\u2019))<\/code><\/pre>\n\u65f6\u95f4\u5b57\u6bb5<\/h1>\n# \u5339\u914d\u65e5\u671f\uff0cdate\nUser.objects.filter(create_time__date=datetime.date(2018, 8, 1))\nUser.objects.filter(create_time__date__gt=datetime.date(2018, 8, 2))\n\n# \u5339\u914d\u5e74\uff0cyear\nUser.objects.filter(create_time__year=2018)\nUser.objects.filter(create_time__year__gte=2018)\n\n# \u5339\u914d\u6708\uff0cmonth\nUser.objects.filter(create_time__month__gt=7)\nUser.objects.filter(create_time__month__gte=7)\n\n# \u5339\u914d\u65e5\uff0cday\nUser.objects.filter(create_time__day=8)\nUser.objects.filter(create_time__day__gte=8)\n\n# \u5339\u914d\u5468\uff0cweek_day\n User.objects.filter(create_time__week_day=2)\nUser.objects.filter(create_time__week_day__gte=2)\n\n# \u5339\u914d\u65f6\uff0chour\nUser.objects.filter(create_time__hour=9)\nUser.objects.filter(create_time__hour__gte=9)\n\n# \u5339\u914d\u5206\uff0cminute\nUser.objects.filter(create_time__minute=15)\nUser.objects.filter(create_time__minute_gt=15)\n\n# \u5339\u914d\u79d2\uff0csecond\nUser.objects.filter(create_time__second=15)\nUser.objects.filter(create_time__second__gte=15)\n\n# \u6309\u5929\u7edf\u8ba1\u5f52\u6863\ntoday = datetime.date.today()\nselect = {'day': connection.ops.date_trunc_sql('day', 'create_time')}\ndeploy_date_count = Task.objects.filter(\n create_time__range=(today - datetime.timedelta(days=7), today)\n).extra(select=select).values('day').annotate(number=Count('id'))<\/code><\/pre>\nQ \u7684\u4f7f\u7528<\/h1>\n
Q\u5bf9\u8c61\u53ef\u4ee5\u5bf9\u5173\u952e\u5b57\u53c2\u6570\u8fdb\u884c\u5c01\u88c5\uff0c\u4ece\u800c\u66f4\u597d\u7684\u5e94\u7528\u591a\u4e2a\u67e5\u8be2\uff0c\u53ef\u4ee5\u7ec4\u5408&(and)\u3001|(or)\u3001~(not)\u64cd\u4f5c\u7b26\u3002<\/p>\n
\u4f8b\u5982\u4e0b\u8fb9\u7684\u8bed\u53e5<\/p>\n
from django.db.models import Q\n\nUser.objects.filter(\n Q(role__startswith='sre_'),\n Q(name='\u516c\u4f17\u53f7') | Q(name='\u8fd0\u7ef4\u5496\u5561\u5427')\n)<\/code><\/pre>\n\u8f6c\u6362\u6210SQL\u8bed\u53e5\u5982\u4e0b\uff1a<\/p>\n
select * from User where role like 'sre_%' and (name='\u516c\u4f17\u53f7' or name='\u8fd0\u7ef4\u5496\u5561\u5427')<\/code><\/pre>\n\u901a\u5e38\u66f4\u591a\u7684\u65f6\u5019\u6211\u4eec\u7528Q\u6765\u505a\u641c\u7d22\u903b\u8f91\uff0c\u6bd4\u5982\u524d\u53f0\u641c\u7d22\u6846\u8f93\u5165\u4e00\u4e2a\u5b57\u7b26\uff0c\u540e\u53f0\u53bb\u6570\u636e\u5e93\u4e2d\u68c0\u7d22\u6807\u9898\u6216\u5185\u5bb9\u4e2d\u662f\u5426\u5305\u542b<\/p>\n
_s = request.GET.get('search')\n\n_t = Blog.objects.all()\nif _s:\n _t = _t.filter(\n Q(title__icontains=_s) |\n Q(content__icontains=_s)\n )\n\nreturn _t<\/code><\/pre>\n\u5916\u952e\uff1aForeignKey<\/h1>\n\n- \u8868\u7ed3\u6784\uff1a<\/li>\n<\/ul>\n
class Role(models.Model):\n name = models.CharField(max_length=16, unique=True)\n\nclass User(models.Model):\n username = models.EmailField(max_length=255, unique=True)\n role = models.ForeignKey(Role, on_delete=models.CASCADE)<\/code><\/pre>\n\n- \u6b63\u5411\u67e5\u8be2:<\/li>\n<\/ul>\n
# \u67e5\u8be2\u7528\u6237\u7684\u89d2\u8272\u540d\n_t = User.objects.get(username='\u8fd0\u7ef4\u5496\u5561\u5427')\n_t.role.name<\/code><\/pre>\n\n- \u53cd\u5411\u67e5\u8be2\uff1a<\/li>\n<\/ul>\n
# \u67e5\u8be2\u89d2\u8272\u4e0b\u5305\u542b\u7684\u6240\u6709\u7528\u6237\n_t = Role.objects.get(name='Role03')\n_t.user_set.all()<\/code><\/pre>\n\n- \u53e6\u4e00\u79cd\u53cd\u5411\u67e5\u8be2\u7684\u65b9\u6cd5\uff1a<\/li>\n<\/ul>\n
_t = Role.objects.get(name='Role03')\n\n# \u8fd9\u79cd\u65b9\u6cd5\u6bd4\u4e0a\u4e00\u79cd_set\u7684\u65b9\u6cd5\u67e5\u8be2\u901f\u5ea6\u8981\u5feb\nUser.objects.filter(role=_t)<\/code><\/pre>\n\n- \u7b2c\u4e09\u79cd\u53cd\u5411\u67e5\u8be2\u7684\u65b9\u6cd5\uff1a<\/li>\n<\/ul>\n
\u5982\u679c\u5916\u952e\u5b57\u6bb5\u6709related_name<\/code>\u5c5e\u6027\uff0c\u4f8b\u5982models\u5982\u4e0b\uff1a<\/p>\nclass User(models.Model):\n username = models.EmailField(max_length=255, unique=True)\n role = models.ForeignKey(Role, on_delete=models.CASCADE,related_name='roleUsers')<\/code><\/pre>\n\u90a3\u4e48\u53ef\u4ee5\u76f4\u63a5\u7528related_name<\/code>\u5c5e\u6027\u53d6\u5230\u67d0\u89d2\u8272\u7684\u6240\u6709\u7528\u6237<\/p>\n_t = Role.objects.get(name = 'Role03')\n_t.roleUsers.all()<\/code><\/pre>\nM2M\uff1aManyToManyField<\/h1>\n\n- \u8868\u7ed3\u6784\uff1a<\/li>\n<\/ul>\n
class Group(models.Model):\n name = models.CharField(max_length=16, unique=True)\n\nclass User(models.Model):\n username = models.CharField(max_length=255, unique=True)\n groups = models.ManyToManyField(Group, related_name='groupUsers')<\/code><\/pre>\n\n- \u6b63\u5411\u67e5\u8be2:<\/li>\n<\/ul>\n
# \u67e5\u8be2\u7528\u6237\u96b6\u5c5e\u7ec4\n_t = User.objects.get(username = '\u8fd0\u7ef4\u5496\u5561\u5427')\n_t.groups.all()<\/code><\/pre>\n\n- \u53cd\u5411\u67e5\u8be2\uff1a<\/li>\n<\/ul>\n
# \u67e5\u8be2\u7ec4\u5305\u542b\u7528\u6237\n_t = Group.objects.get(name = 'groupC')\n_t.user_set.all()<\/code><\/pre>\n\u540c\u6837M2M\u5b57\u6bb5\u5982\u679c\u6709related_name<\/code>\u5c5e\u6027\uff0c\u90a3\u4e48\u53ef\u4ee5\u76f4\u63a5\u7528\u4e0b\u8fb9\u7684\u65b9\u5f0f\u53cd\u67e5<\/p>\n_t = Group.objects.get(name = 'groupC')\n_t.groupUsers.all()<\/code><\/pre>\nget_object_or_404<\/h1>\n
\u6b63\u5e38\u5982\u679c\u6211\u4eec\u8981\u53bb\u6570\u636e\u5e93\u91cc\u641c\u7d22\u67d0\u4e00\u6761\u6570\u636e\u65f6\uff0c\u901a\u5e38\u4f7f\u7528\u4e0b\u8fb9\u7684\u65b9\u6cd5\uff1a<\/p>\n
_t = User.objects.get(id=734)<\/code><\/pre>\n\u4f46\u5f53id=724<\/code>\u7684\u6570\u636e\u4e0d\u5b58\u5728\u65f6\uff0c\u7a0b\u5e8f\u5c06\u4f1a\u629b\u51fa\u4e00\u4e2a\u9519\u8bef<\/p>\nabcer.models.DoesNotExist: User matching query does not exist.<\/code><\/pre>\n\u4e3a\u4e86\u7a0b\u5e8f\u517c\u5bb9\u548c\u5f02\u5e38\u5224\u65ad\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u4e0b\u8fb9\u4e24\u79cd\u65b9\u5f0f:<\/p>\n
\n- \u65b9\u5f0f\u4e00\uff1a
get<\/code>\u6539\u4e3afilter<\/code><\/li>\n<\/ul>\n_t = User.objects.filter(id=724)\n# \u53d6\u51fa_t\u4e4b\u540e\u518d\u53bb\u5224\u65ad_t\u662f\u5426\u5b58\u5728<\/code><\/pre>\n\n- \u65b9\u5f0f\u4e8c\uff1a\u4f7f\u7528
get_object_or_404<\/code><\/li>\n<\/ul>\nfrom django.shortcuts import get_object_or_404\n\n_t = get_object_or_404(User, id=724)\n# get_object_or_404\u65b9\u6cd5\uff0c\u5b83\u4f1a\u5148\u8c03\u7528django\u7684get\u65b9\u6cd5\uff0c\u5982\u679c\u67e5\u8be2\u7684\u5bf9\u8c61\u4e0d\u5b58\u5728\u7684\u8bdd\uff0c\u5219\u629b\u51fa\u4e00\u4e2aHttp404\u7684\u5f02\u5e38<\/code><\/pre>\n\u5b9e\u73b0\u65b9\u6cd5\u7c7b\u4f3c\u4e8e\u4e0b\u8fb9\u8fd9\u6837\uff1a<\/p>\n
from django.http import Http404\n\ntry:\n _t = User.objects.get(id=724)\nexcept User.DoesNotExist:\n raise Http404<\/code><\/pre>\nget_or_create<\/h1>\n
\u987e\u540d\u601d\u4e49\uff0c\u67e5\u627e\u4e00\u4e2a\u5bf9\u8c61\u5982\u679c\u4e0d\u5b58\u5728\u5219\u521b\u5efa\uff0c\u5982\u4e0b\uff1a<\/p>\n
object, created = User.objects.get_or_create(username='\u8fd0\u7ef4\u5496\u5561\u5427')<\/code><\/pre>\n\u8fd4\u56de\u4e00\u4e2a\u7531object\u548ccreated\u7ec4\u6210\u7684\u5143\u7ec4\uff0c\u5176\u4e2dobject\u5c31\u662f\u4e00\u4e2a\u67e5\u8be2\u5230\u7684\u6216\u8005\u662f\u88ab\u521b\u5efa\u7684\u5bf9\u8c61\uff0ccreated\u662f\u4e00\u4e2a\u8868\u793a\u662f\u5426\u521b\u5efa\u4e86\u65b0\u5bf9\u8c61\u7684\u5e03\u5c14\u503c<\/p>\n
\u5b9e\u73b0\u65b9\u5f0f\u7c7b\u4f3c\u4e8e\u4e0b\u8fb9\u8fd9\u6837\uff1a<\/p>\n
try:\n object = User.objects.get(username='\u8fd0\u7ef4\u5496\u5561\u5427')\n\n created = False\nexception User.DoesNoExist:\n object = User(username='\u8fd0\u7ef4\u5496\u5561\u5427')\n object.save()\n\n created = True\n\nreturen object, created<\/code><\/pre>\n\u6267\u884c\u539f\u751fSQL<\/h1>\n
Django\u4e2d\u80fd\u7528ORM\u7684\u5c31\u7528\u5b83ORM\u5427\uff0c\u4e0d\u5efa\u8bae\u6267\u884c\u539f\u751fSQL\uff0c\u53ef\u80fd\u4f1a\u6709\u4e00\u4e9b\u5b89\u5168\u95ee\u9898\uff0c\u5982\u679c\u5b9e\u5728\u662fSQL\u592a\u590d\u6742ORM\u5b9e\u73b0\u4e0d\u4e86\uff0c\u90a3\u5c31\u770b\u770b\u4e0b\u8fb9\u6267\u884c\u539f\u751fSQL\u7684\u65b9\u6cd5\uff0c\u8ddf\u76f4\u63a5\u4f7f\u7528pymysql\u57fa\u672c\u4e00\u81f4\u4e86<\/p>\n
from django.db import connection\n\nwith connection.cursor() as cursor:\n cursor.execute('select * from accounts_User')\n row = cursor.fetchall()\n\nreturn row<\/code><\/pre>\n\u6ce8\u610f\u8fd9\u91cc\u8868\u540d\u5b57\u8981\u7528app\u540d+\u4e0b\u5212\u7ebf+model\u540d<\/strong>\u7684\u65b9\u5f0f<\/p>\n","protected":false},"excerpt":{"rendered":"Django\u5f00\u53d1\u8fc7\u7a0b\u4e2d\u5bf9\u8868(model)\u7684\u589e\u5220\u6539\u67e5\u662f\u6700\u5e38\u7528\u7684\u529f\u80fd\u4e4b\u4e00\uff0c\u672c\u6587\u4ecb\u7ecd\u7b14\u8005\u5728\u4f7f\u7528model \u64cd\u4f5c\u8fc7\u7a0b\u4e2d\u9047\u5230\u7684\u4e00\u4e9b\u64cd\u4f5c\u3002 mode \u2026 …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[27],"tags":[19,18],"_links":{"self":[{"href":"\/index.php?rest_route=\/wp\/v2\/posts\/1048"}],"collection":[{"href":"\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1048"}],"version-history":[{"count":1,"href":"\/index.php?rest_route=\/wp\/v2\/posts\/1048\/revisions"}],"predecessor-version":[{"id":1049,"href":"\/index.php?rest_route=\/wp\/v2\/posts\/1048\/revisions\/1049"}],"wp:attachment":[{"href":"\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1048"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1048"},{"taxonomy":"post_tag","embeddable":true,"href":"\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1048"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}