{"id":82,"date":"2023-03-15T19:48:09","date_gmt":"2023-03-15T11:48:09","guid":{"rendered":"http:\/\/idc.birk.cn\/?p=82"},"modified":"2023-04-20T14:36:58","modified_gmt":"2023-04-20T06:36:58","slug":"python-django-models%e5%ad%97%e6%ae%b5%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/idc.birk.cn\/?p=82","title":{"rendered":"Python Django Models\u5b57\u6bb5\u8be6\u89e3"},"content":{"rendered":"<h1 class=\"postTitle\"><span style=\"font-size: 18px\">Models\u5b57\u6bb5\u8be6\u89e3<\/span><\/h1>\n<div class=\"postBody\">\n<div id=\"cnblogs_post_body\" class=\"blogpost-body blogpost-body-html\">\n<h3>AutoField(Field)<\/h3>\n<p>int\u7c7b\u578b\u81ea\u589e\u5217\uff0c\u5fc5\u987b\u586b\u5165\u53c2\u6570\u00a0<span class=\"cnblogs_code\">primary_key=True<\/span><\/p>\n<h3>BigAutoField(AutoField)<\/h3>\n<p>bigint\u7c7b\u578b\u81ea\u589e\u5217\uff0c\u5fc5\u987b\u586b\u5165\u53c2\u6570\u00a0<span class=\"cnblogs_code\">primary_key=True<\/span><\/p>\n<p><strong>\u6ce8\u610f\uff1a<\/strong><\/p>\n<p>\u5728models\u4e2d\u5982\u679c\u6ca1\u6709\u81ea\u5b9a\u4e49\u81ea\u589e\u5217\uff0c\u5219\u4f1a\u81ea\u52a8\u521b\u5efa\u4e00\u4e2a\u5217\u540d\u4e3aid\u7684\u81ea\u589e\u5217<\/p>\n<div class=\"cnblogs_code\">\n<p><img decoding=\"async\" id=\"code_img_opened_cfa0dde6-d4e2-4dd2-ac15-6ddd82e45ccf\" class=\"code_img_opened mBox\"  src=\"\/wp-content\/uploads\/replace\/961ddebeb323a10fe0623af514929fc1.gif\" alt=\"Python Django Models\u5b57\u6bb5\u8be6\u89e3\" \/><\/p>\n<div id=\"cnblogs_code_open_cfa0dde6-d4e2-4dd2-ac15-6ddd82e45ccf\" class=\"cnblogs_code_hide\">\n<pre>from django.db import models\r\n\r\nclass User(models.Model):\r\n    # \u7531\u4e8e\u6ca1\u6709\u81ea\u5b9a\u4e49\u81ea\u589e\u5217\uff0c\u6240\u4ee5\u4f1a\u81ea\u52a8\u521b\u5efa\u4e00\u4e2a\u540d\u4e3aid\u7684\u81ea\u589e\u5217\r\n    name = models.CharField(max_length=32)<\/pre>\n<\/div>\n<\/div>\n<p>\u5982\u679c\u81ea\u5df1\u5b9a\u4e49\u4e86\u81ea\u589e\u5217\uff0c\u5c31\u4e0d\u4f1a\u521b\u5efa\u4e86<\/p>\n<div class=\"cnblogs_code\">\n<p><img decoding=\"async\" id=\"code_img_opened_398fc16f-060d-4f84-978c-d1567875c9fc\" class=\"code_img_opened mBox\"  src=\"\/wp-content\/uploads\/replace\/961ddebeb323a10fe0623af514929fc1.gif\" alt=\"Python Django Models\u5b57\u6bb5\u8be6\u89e3\" \/><\/p>\n<div id=\"cnblogs_code_open_398fc16f-060d-4f84-978c-d1567875c9fc\" class=\"cnblogs_code_hide\">\n<pre>from django.db import models\r\n\r\nclass User(models.Model):\r\n    nid = modelsAutoField(primary_key=True)\r\n    name = models.CharField(max_length=32)<\/pre>\n<\/div>\n<\/div>\n<h3>SmallIntegerField(IntegerField)<\/h3>\n<p>\u5c0f\u6574\u578b \u00a0 -32768 ~ 32767<\/p>\n<h3>PositiveSmallIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField)<\/h3>\n<p>\u6b63\u5c0f\u6b63\u6570 \u00a0 0 ~ 32767<\/p>\n<h3>IntegerField(Field)<\/h3>\n<p>\u6574\u6570\u7c7b\u578b(\u6709\u7b26\u53f7) \u00a0 \u00a0-2147483648 \uff5e 2147483647<\/p>\n<h3>PositiveIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField)<\/h3>\n<p>\u6b63\u6574\u6570 \u00a0 \u00a00 \uff5e 2147483647<\/p>\n<h3>BigIntegerField(IntegerField)<\/h3>\n<p>\u957f\u6574\u578b(\u6709\u7b26\u53f7) \u00a0 \u00a0-9223372036854775808 \uff5e 9223372036854775807<\/p>\n<h3>BooleanField(Field)<\/h3>\n<p>\u5e03\u5c14\u7c7b\u578b<\/p>\n<h3>NullBooleanField(Field)<\/h3>\n<p>\u53ef\u4ee5\u4e3a\u7a7a\u7684\u5e03\u5c14\u503c<\/p>\n<h3>CharField(Field)<\/h3>\n<p>\u5b57\u7b26\u7c7b\u578b\uff0c\u5fc5\u987b\u63d0\u4f9bmax_length\u53c2\u6570\uff0cmax_length\u8868\u793a\u5b57\u7b26\u957f\u5ea6<\/p>\n<h3>TextField(Field)<\/h3>\n<p>\u6587\u672c\u7c7b\u578b<\/p>\n<h3>EmailField(CharField)<\/h3>\n<p>\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u4e3aDjango Admin\u4ee5\u53caModelForm\u4e2d\u63d0\u4f9b\u9a8c\u8bc1\u673a\u5236<\/p>\n<h3>IPAddressField(Field)<\/h3>\n<p>\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u4e3aDjango Admin\u4ee5\u53caModelForm\u4e2d\u63d0\u4f9b\u9a8c\u8bc1IPV4\u673a\u5236<\/p>\n<h3>GenericIPAddressField(Field)<\/h3>\n<p>\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u4e3aDjango Admin\u4ee5\u53caModelForm\u4e2d\u63d0\u4f9b\u9a8c\u8bc1 IPV4\u548cIPV6<\/p>\n<p>\u53c2\u6570\uff1a<\/p>\n<ul>\n<li>protocol\uff0c\u7528\u4e8e\u6307\u5b9aIPV6\u6216IPV4\uff0c 'both'\uff0c'ipv4'\uff0c'ipv6'<\/li>\n<li>unpack_ipv4\uff0c\u5982\u679c\u6307\u5b9a\u4e3aTrue\uff0c\u5219\u8f93\u5165::ffff:192.0.2.1\u7684\u65f6\u5019\uff0c\u4e5f\u53ef\u89e3\u6790\u4e3a192.0.2.1\uff0c\u4f46\u662f\u60f3\u8981\u5f00\u542f\u6b64\u529f\u80fd\uff0c\u9700\u8981protocol='both'<\/li>\n<\/ul>\n<h3>URLField(CharField)<\/h3>\n<p>\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u4e3aDjango Admin\u4ee5\u53caModelForm\u4e2d\u63d0\u4f9b\u9a8c\u8bc1URL<\/p>\n<h3>SlugField(CharField)<\/h3>\n<p>\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u4e3aDjango Admin\u4ee5\u53caModelForm\u4e2d\u63d0\u4f9b\u9a8c\u8bc1\u652f\u6301 \u5b57\u6bcd\u3001\u6570\u5b57\u3001\u4e0b\u5212\u7ebf\u3001\u8fde\u63a5\u7b26\uff08\u51cf\u53f7\uff09<\/p>\n<h3>CommaSeparatedIntegerField(CharField)<\/h3>\n<p>\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u683c\u5f0f\u5fc5\u987b\u4e3a\u9017\u53f7\u5206\u5272\u7684\u6570\u5b57<\/p>\n<h3>UUIDField(Field)<\/h3>\n<p>\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u4e3aDjango Admin\u4ee5\u53caModelForm\u4e2d\u63d0\u4f9b\u5bf9UUID\u683c\u5f0f\u7684\u9a8c\u8bc1<\/p>\n<h3>FilePathField(Field)<\/h3>\n<p>\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u4e3aDjango Admin\u4ee5\u53caModelForm\u4e2d\u63d0\u4f9b\u8bfb\u53d6\u6587\u4ef6\u5939\u4e0b\u6587\u4ef6\u7684\u529f\u80fd<\/p>\n<p>\u53c2\u6570\uff1a<\/p>\n<ul>\n<li>path\uff1a\u6587\u4ef6\u5939\u8def\u5f84<\/li>\n<li>match=None\uff1a\u6b63\u5219\u5339\u914d<\/li>\n<li>recursive=False\uff1a\u9012\u5f52\u4e0b\u9762\u7684\u6587\u4ef6\u5939<\/li>\n<li>allow_files=True\uff1a\u5141\u8bb8\u6587\u4ef6<\/li>\n<li>allow_folders=False\uff1a\u5141\u8bb8\u6587\u4ef6\u5939<\/li>\n<\/ul>\n<h3>FileField(Field)<\/h3>\n<p>\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u8def\u5f84\u4fdd\u5b58\u5728\u6570\u636e\u5e93\uff0c\u6587\u4ef6\u4e0a\u4f20\u5230\u6307\u5b9a\u76ee\u5f55<\/p>\n<p>\u53c2\u6570\uff1a<\/p>\n<ul>\n<li>upload_to=\" \"\uff1a\u4e0a\u4f20\u6587\u4ef6\u7684\u4fdd\u5b58\u8def\u5f84<\/li>\n<li>storage=None\uff1a\u50a8\u5b58\u7ec4\u4ef6\uff0c\u9ed8\u8ba4django.core.files.storage.FileSystemStorage<\/li>\n<\/ul>\n<h3>ImageField(FileField)<\/h3>\n<p>\u5b57\u7b26\u4e32\uff0c\u8def\u5f84\u4fdd\u5b58\u5728\u6570\u636e\u5e93\uff0c\u6587\u4ef6\u4e0a\u4f20\u5230\u6307\u5b9a\u76ee\u5f55<\/p>\n<p>\u53c2\u6570\uff1a<\/p>\n<ul>\n<li>upload_to=\" \"\uff1a\u4e0a\u4f20\u6587\u4ef6\u7684\u4fdd\u5b58\u8def\u5f84<\/li>\n<li>storage=None\uff1a\u5b58\u50a8\u7ec4\u4ef6\uff0c\u9ed8\u8ba4django.core.files.storage.FileSystemStorage<\/li>\n<li>width_field=None\uff1a\u4e0a\u4f20\u56fe\u7247\u7684\u9ad8\u5ea6\u4fdd\u5b58\u7684\u6570\u636e\u5e93\u5b57\u6bb5\u540d\uff08\u5b57\u7b26\u4e32\uff09<\/li>\n<li>height_field=None\uff1a\u4e0a\u4f20\u56fe\u7247\u7684\u5bbd\u5ea6\u4fdd\u5b58\u7684\u6570\u636e\u5e93\u5b57\u6bb5\u540d\uff08\u5b57\u7b26\u4e32\uff09<\/li>\n<\/ul>\n<h3>DateTimeField(DateField)<\/h3>\n<p>\u65e5\u671f+\u65f6\u95f4 \u683c\u5f0f \u00a0 YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]<\/p>\n<h3>DateField(DateTimeCheckMixin, Field)<\/h3>\n<p>\u65e5\u671f\u683c\u5f0f \u00a0 \u00a0YYYY-MM-DD<\/p>\n<h3>TimeField(DateTimeCheckMixin, Field)<\/h3>\n<p>\u65f6\u95f4\u683c\u5f0f \u00a0 HH:MM[:ss[.uuuuuu]]<\/p>\n<h3>DurationField(Field)<\/h3>\n<p>\u957f\u6574\u6570\uff0c\u65f6\u95f4\u95f4\u9694\uff0c\u6570\u636e\u5e93\u4e2d\u6309\u7167bigint\u50a8\u5b58\uff0cORM\u4e2d\u83b7\u53d6\u7684\u503c\u4e3adatetime.timedelta\u7c7b\u578b<\/p>\n<h3>FloatField(Field)<\/h3>\n<p>\u6d6e\u70b9\u578b<\/p>\n<h3>DecimalField(Field)<\/h3>\n<p>\u5341\u8fdb\u5236\u5c0f\u6570<\/p>\n<p>\u53c2\u6570\uff1a<\/p>\n<ul>\n<li>max_digits\uff1a\u6570\u636e\u603b\u957f\u5ea6<\/li>\n<li>decimal_places\uff1a\u5c0f\u6570\u4f4d\u957f\u5ea6<\/li>\n<\/ul>\n<h3>BinaryField(Field)<\/h3>\n<p>\u4e8c\u8fdb\u5236\u7c7b\u578b<\/p>\n<h3>\u5404\u4e2a\u5b57\u6bb5\u5bf9\u5e94\u5728\u6570\u636e\u5e93\u4e2d\u7684\u7c7b\u578b<\/h3>\n<div class=\"cnblogs_code\">\n<p><img decoding=\"async\" id=\"code_img_opened_aa9deb10-9c57-4232-89cd-36eee82e8665\" class=\"code_img_opened mBox\"  src=\"\/wp-content\/uploads\/replace\/961ddebeb323a10fe0623af514929fc1.gif\" alt=\"Python Django Models\u5b57\u6bb5\u8be6\u89e3\" \/><\/p>\n<div id=\"cnblogs_code_open_aa9deb10-9c57-4232-89cd-36eee82e8665\" class=\"cnblogs_code_hide\">\n<div class=\"cnblogs_code_toolbar\"><\/div>\n<pre>'AutoField': 'integer AUTO_INCREMENT',\r\n'BigAutoField': 'bigint AUTO_INCREMENT',\r\n'BinaryField': 'longblob',\r\n'BooleanField': 'bool',\r\n'CharField': 'varchar(%(max_length)s)',\r\n'CommaSeparatedIntegerField': 'varchar(%(max_length)s)',\r\n'DateField': 'date',\r\n'DateTimeField': 'datetime',\r\n'DecimalField': 'numeric(%(max_digits)s, %(decimal_places)s)',\r\n'DurationField': 'bigint',\r\n'FileField': 'varchar(%(max_length)s)',\r\n'FilePathField': 'varchar(%(max_length)s)',\r\n'FloatField': 'double precision',\r\n'IntegerField': 'integer',\r\n'BigIntegerField': 'bigint',\r\n'IPAddressField': 'char(15)',\r\n'GenericIPAddressField': 'char(39)',\r\n'NullBooleanField': 'bool',\r\n'OneToOneField': 'integer',\r\n'PositiveIntegerField': 'integer UNSIGNED',\r\n'PositiveSmallIntegerField': 'smallint UNSIGNED',\r\n'SlugField': 'varchar(%(max_length)s)',\r\n'SmallIntegerField': 'smallint',\r\n'TextField': 'longtext',\r\n'TimeField': 'time',\r\n'UUIDField': 'char(32)',<\/pre>\n<div class=\"cnblogs_code_toolbar\"><\/div>\n<\/div>\n<\/div>\n<h2>\u5b57\u6bb5\u53c2\u6570\u4ecb\u7ecd<\/h2>\n<p>\u8fd9\u91cc\u4ecb\u7ecd\u7684\u5b57\u6bb5\u53c2\u6570\u662f\u6307\u6240\u6709\u5b57\u6bb5\u5747\u9002\u7528\u7684\u53c2\u6570\uff0c\u6bcf\u4e2a\u5b57\u6bb5\u72ec\u6709\u7684\u53c2\u6570\u5df2\u5728\u4e0a\u9762\u5355\u72ec\u4ecb\u7ecd<\/p>\n<h3>null<\/h3>\n<p>\u6307\u5b9a\u6570\u636e\u5e93\u5b57\u6bb5\u662f\u5426\u53ef\u4ee5\u4e3a\u7a7a<\/p>\n<h3>db_column<\/h3>\n<p>\u6307\u5b9a\u5728\u6570\u636e\u5e93\u8868\u4e2d\u8fd9\u4e00\u5217\u7684\u5217\u540d\uff0c\u5982\u679c\u6ca1\u6709\u6307\u5b9a\uff0c\u5c31\u4f1a\u9ed8\u8ba4\u4f7f\u7528\u5b57\u6bb5\u540d<\/p>\n<h3>default<\/h3>\n<p>\u5b57\u6bb5\u7684\u9ed8\u8ba4\u503c\uff0c\u5982\u679c\u5728\u63d2\u5165\u4e00\u6761\u8bb0\u5f55\u65f6\u6ca1\u6709\u4e3a\u8be5\u5217\u8d4b\u503c\uff0c\u90a3\u4e48\u5c31\u4f1a\u4f7f\u7528\u8be5\u9ed8\u8ba4\u503c<\/p>\n<h3>primary_key<\/h3>\n<p>\u6307\u5b9a\u8be5\u5b57\u6bb5\u662f\u5426\u4e3a\u4e3b\u952e<\/p>\n<h3>db_index<\/h3>\n<p>\u662f\u5426\u4e3a\u8be5\u5b57\u6bb5\u5efa\u7acb\u7d22\u5f15\uff0c\u8fd9\u79cd\u7d22\u5f15\u53ea\u662f\u5355\u7eaf\u7684\u52a0\u5feb\u67e5\u627e\u901f\u5ea6\uff0c\u5e76\u65e0\u5176\u4ed6\u4f5c\u7528<\/p>\n<h3>unique<\/h3>\n<p>\u662f\u5426\u4e3a\u8be5\u5b57\u6bb5\u5efa\u7acb\u552f\u4e00\u7d22\u5f15\uff0c\u8fd9\u79cd\u7d22\u5f15\u9664\u4e86\u53ef\u4ee5\u52a0\u5feb\u67e5\u8be2\u901f\u5ea6\u4ee5\u5916\uff0c\u8fd8\u80fd\u9650\u5236\u8be5\u5b57\u6bb5\u63d2\u5165\u7684\u503c\u552f\u4e00<\/p>\n<h3>unique_for_date<\/h3>\n<p>\u662f\u5426\u4e3a\u5b57\u6bb5\u7684\u65e5\u671f\u90e8\u5206\u5efa\u7acb\u552f\u4e00\u7d22\u5f15\uff0c\u6709\u7684\u65f6\u5019\u6211\u4eec\u67e5\u627e\u53ea\u5173\u6ce8\u65e5\u671f\uff0c\u5bf9\u5b57\u6bb5\u7684\u5176\u4ed6\u90e8\u5206\u5e76\u4e0d\u611f\u5174\u8da3\uff0c\u90a3\u4e48\u5c31\u53ef\u4ee5\u4e3a\u65e5\u671f\u5355\u72ec\u5efa\u7acb\u7d22\u5f15\uff0c\u4ee5\u6b64\u6765\u52a0\u5feb\u67e5\u627e\u901f\u5ea6<\/p>\n<h3>unique_for_month<\/h3>\n<p>\u662f\u5426\u4e3a\u5b57\u6bb5\u7684\u6708\u90e8\u5206\u5efa\u7acb\u552f\u4e00\u7d22\u5f15\uff0c\u5982\u679c\u6709\u7684\u65f6\u5019\u53ea\u5173\u6ce8\u6708\u4efd\uff0c\u540c\u6837\u4e5f\u53ef\u4ee5\u53ea\u5bf9\u5b57\u6bb5\u6708\u7684\u90e8\u5206\u5efa\u7acb\u7d22\u5f15<\/p>\n<h3>unique_for_year<\/h3>\n<p>\u662f\u5426\u4e3a\u5b57\u6bb5\u7684\u5e74\u90e8\u5206\u5efa\u7acb\u552f\u4e00\u7d22\u5f15\uff0c\u5982\u679c\u6709\u65f6\u5019\u53ea\u5173\u6ce8\u5b57\u6bb5\u7684\u5e74\u4efd\uff0c\u540c\u6837\u53ef\u4ee5\u53ea\u5bf9\u5e74\u7684\u90e8\u5206\u5efa\u7acb\u552f\u4e00\u7d22\u5f15<\/p>\n<h3>verbose_name<\/h3>\n<p>\u8be5\u53c2\u6570\u662f\u4e3a\u5b57\u6bb5\u5728Admin\u4e2d\u663e\u793a\u800c\u8bbe\u7acb\u7684\uff0c\u76f8\u5f53\u4e8e\u4e3a\u8be5\u5b57\u6bb5\u53d6\u4e86\u4e00\u4e2a\u5728admin\u4e2d\u663e\u793a\u7684\u540d\u5b57<\/p>\n<h3>blank<\/h3>\n<p>\u8be5\u53c2\u6570\u662f\u4e3aAdmin\u8bbe\u7acb\u7684\uff0c\u662f\u5426\u5141\u8bb8\u5728Admin\u4e2d\u8f93\u5165\u4e3a\u7a7a<\/p>\n<h3>editable<\/h3>\n<p>\u8be5\u53c2\u6570\u662f\u4e3aAdmin\u8bbe\u7acb\u7684\uff0c\u662f\u5426\u5141\u8bb8Admin\u4e2d\u7f16\u8f91\u8be5\u5b57\u6bb5<\/p>\n<h3>help_text<\/h3>\n<p>\u8be5\u53c2\u6570\u662f\u4e3aAdmin\u8bbe\u7acb\u7684\uff0c\u5728Admin\u4e2d\u663e\u793a\u8be5\u5b57\u6bb5\u7684\u63d0\u793a\u4fe1\u606f<\/p>\n<h3>choices<\/h3>\n<p>\u8be5\u53c2\u6570\u662f\u4e3aAdmin\u8bbe\u7acb\u7684\uff0c\u5728Admin\u4e2d\u4e0b\u62c9\u9009\u6846\u7684\u5185\u5bb9<\/p>\n<p>\u5982\uff1a<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_8570\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python plain\">gf\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.IntegerField(choices<\/code><code class=\"python keyword\">=<\/code><code class=\"python plain\">[(<\/code><code class=\"python value\">0<\/code><code class=\"python plain\">,\u00a0<\/code><code class=\"python string\">'\u5c0f\u59e8\u5988'<\/code><code class=\"python plain\">), (<\/code><code class=\"python value\">1<\/code><code class=\"python plain\">,\u00a0<\/code><code class=\"python string\">'\u5927\u8868\u59d0'<\/code><code class=\"python plain\">), ], default<\/code><code class=\"python keyword\">=<\/code><code class=\"python value\">1<\/code><code class=\"python plain\">)<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<h3>error_messages<\/h3>\n<p>\u81ea\u5b9a\u4e49\u9519\u8bef\u4fe1\u606f(\u5b57\u5178\u7c7b\u578b)\uff0c\u4ece\u800c\u5b9a\u5236\u60f3\u8981\u663e\u793a\u7684\u9519\u8bef\u4fe1\u606f\uff0c\u5b57\u5178\u7684\u952e\u662f\u53c2\u6570\u540d\uff0c\u5982\uff1aunique,invalid,invalid_choice\u7b49\uff0c\u5b57\u5178\u7684\u503c\u662f\u5982\u679c\u8fdd\u53cd\u4e86\u76f8\u5bf9\u5e94\u7684\u89c4\u5219\u800c\u63d0\u793a\u7684\u9519\u8bef\u4fe1\u606f\uff0c\u5982\uff1a<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_294752\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<div class=\"line number2 index1 alt1\">2<\/div>\n<div class=\"line number3 index2 alt2\">3<\/div>\n<div class=\"line number4 index3 alt1\">4<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python plain\">error_messages<\/code><code class=\"python keyword\">=<\/code><code class=\"python plain\">{<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python string\">'unique'<\/code><code class=\"python plain\">:\u00a0<\/code><code class=\"python string\">'\u8f93\u5165\u5185\u5bb9\u5df2\u5b58\u5728'<\/code><code class=\"python plain\">,<\/code><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python string\">'invalid'<\/code><code class=\"python plain\">:\u00a0<\/code><code class=\"python string\">'\u8f93\u5165\u683c\u5f0f\u9519\u8bef'<\/code><code class=\"python plain\">,<\/code><\/div>\n<div class=\"line number4 index3 alt1\"><code class=\"python plain\">}<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<h3>validators<\/h3>\n<p>\u81ea\u5b9a\u4e49\u9a8c\u8bc1\u89c4\u5219(\u5217\u8868\u7c7b\u578b)\uff0c\u5982\uff1a<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_973016\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<div class=\"line number2 index1 alt1\">2<\/div>\n<div class=\"line number3 index2 alt2\">3<\/div>\n<div class=\"line number4 index3 alt1\">4<\/div>\n<div class=\"line number5 index4 alt2\">5<\/div>\n<div class=\"line number6 index5 alt1\">6<\/div>\n<div class=\"line number7 index6 alt2\">7<\/div>\n<div class=\"line number8 index7 alt1\">8<\/div>\n<div class=\"line number9 index8 alt2\">9<\/div>\n<div class=\"line number10 index9 alt1\">10<\/div>\n<div class=\"line number11 index10 alt2\">11<\/div>\n<div class=\"line number12 index11 alt1\">12<\/div>\n<div class=\"line number13 index12 alt2\">13<\/div>\n<div class=\"line number14 index13 alt1\">14<\/div>\n<div class=\"line number15 index14 alt2\">15<\/div>\n<div class=\"line number16 index15 alt1\">16<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python keyword\">from<\/code>\u00a0<code class=\"python plain\">django.core.validators\u00a0<\/code><code class=\"python keyword\">import<\/code>\u00a0<code class=\"python plain\">RegexValidator<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python keyword\">from<\/code>\u00a0<code class=\"python plain\">django.core.validators\u00a0<\/code><code class=\"python keyword\">import<\/code>\u00a0<code class=\"python plain\">EmailValidator,URLValidator,DecimalValidator,<\/code><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">MaxLengthValidator,MinLengthValidator,MaxValueValidator,MinValueValidator<\/code><\/div>\n<div class=\"line number4 index3 alt1\"><\/div>\n<div class=\"line number5 index4 alt2\"><code class=\"python plain\">name\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.CharField(<\/code><\/div>\n<div class=\"line number6 index5 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">max_length<\/code><code class=\"python keyword\">=<\/code><code class=\"python value\">32<\/code><code class=\"python plain\">,<\/code><\/div>\n<div class=\"line number7 index6 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">validators<\/code><code class=\"python keyword\">=<\/code><code class=\"python plain\">[<\/code><\/div>\n<div class=\"line number8 index7 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">RegexValidator(r<\/code><code class=\"python string\">'root_d+'<\/code><code class=\"python plain\">, message<\/code><code class=\"python keyword\">=<\/code><code class=\"python string\">'\u9519\u4e86'<\/code><code class=\"python plain\">,\u00a0 code<\/code><code class=\"python keyword\">=<\/code><code class=\"python string\">\"c1\"<\/code><code class=\"python plain\">),<\/code><\/div>\n<div class=\"line number9 index8 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">RegexValidator(r<\/code><code class=\"python string\">'root_11111d+'<\/code><code class=\"python plain\">, message<\/code><code class=\"python keyword\">=<\/code><code class=\"python string\">\"\u53c8\u9519\u4e86\"<\/code><code class=\"python plain\">, code<\/code><code class=\"python keyword\">=<\/code><code class=\"python string\">'c2'<\/code><code class=\"python plain\">),<\/code><\/div>\n<div class=\"line number10 index9 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">EmailValidator(message<\/code><code class=\"python keyword\">=<\/code><code class=\"python string\">'\u8fd8\u662f\u9519\u4e86'<\/code><code class=\"python plain\">, code<\/code><code class=\"python keyword\">=<\/code><code class=\"python string\">'c3'<\/code><code class=\"python plain\">), ],<\/code><\/div>\n<div class=\"line number11 index10 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">error_messages<\/code><code class=\"python keyword\">=<\/code><code class=\"python plain\">{<\/code><\/div>\n<div class=\"line number12 index11 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python string\">'c1'<\/code><code class=\"python plain\">:\u00a0<\/code><code class=\"python string\">'\u9519\u8bef\u4fe1\u606f1'<\/code><code class=\"python plain\">,<\/code><\/div>\n<div class=\"line number13 index12 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python string\">'c2'<\/code><code class=\"python plain\">:\u00a0<\/code><code class=\"python string\">'\u9519\u8bef\u4fe1\u606f2'<\/code><code class=\"python plain\">,<\/code><\/div>\n<div class=\"line number14 index13 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python string\">'c3'<\/code><code class=\"python plain\">:\u00a0<\/code><code class=\"python string\">'\u9519\u8bef\u4fe1\u606f3'<\/code><code class=\"python plain\">,<\/code><\/div>\n<div class=\"line number15 index14 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">}<\/code><\/div>\n<div class=\"line number16 index15 alt1\"><code class=\"python plain\">)<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<h2>\u5143\u4fe1\u606f<\/h2>\n<p>\u5728models\u4e2d\u521b\u5efa\u7684\u7c7b\u9664\u4e86\u53ef\u4ee5\u5199\u5404\u79cd\u5404\u6837\u7684\u5b57\u6bb5\u4ee5\u5916\uff0c\u8fd8\u53ef\u4ee5\u5728\u91cc\u9762\u5199\u4e00\u4e2a\u7c7b\u6765\u5bf9\u6574\u4e2a\u8868\u505a\u64cd\u4f5c\uff0c\u8fd9\u4e2a\u7c7b\u7684\u540d\u5b57\u662fMeta\uff0c\u5728\u91cc\u9762\u540c\u6837\u662f\u901a\u8fc7\u5b57\u6bb5\u6765\u64cd\u4f5c<\/p>\n<p>\u4f8b\uff1a<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_871053\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<div class=\"line number2 index1 alt1\">2<\/div>\n<div class=\"line number3 index2 alt2\">3<\/div>\n<div class=\"line number4 index3 alt1\">4<\/div>\n<div class=\"line number5 index4 alt2\">5<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python keyword\">class<\/code>\u00a0<code class=\"python plain\">UserInfo(models.Model):<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">nid\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.AutoField(primary_key<\/code><code class=\"python keyword\">=<\/code><code class=\"python color1\">True<\/code><code class=\"python plain\">)<\/code><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">username\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.CharField(max_length<\/code><code class=\"python keyword\">=<\/code><code class=\"python value\">32<\/code><code class=\"python plain\">)<\/code><\/div>\n<div class=\"line number4 index3 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python keyword\">class<\/code>\u00a0<code class=\"python plain\">Meta:<\/code><\/div>\n<div class=\"line number5 index4 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">db_table\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python string\">\"User\"<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<p>\u4e0b\u9762\u5bf9\u8be5\u7c7b\u4e2d\u7684\u5b57\u6bb5\u505a\u4ecb\u7ecd<\/p>\n<h3>db_table<\/h3>\n<p>\u5728\u6570\u636e\u5e93\u4e2d\u751f\u6210\u7684\u8868\u7684\u540d\u5b57\uff0c\u9ed8\u8ba4\u662f\uff1aapp\u540d\u79f0_\u7c7b\u540d<\/p>\n<h3>index_together<\/h3>\n<p>\u4e3a\u4e24\u4e2a\u6216\u591a\u4e2a\u5b57\u6bb5\u5171\u540c\u5efa\u7acb\u7d22\u5f15<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_808009\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<div class=\"line number2 index1 alt1\">2<\/div>\n<div class=\"line number3 index2 alt2\">3<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python plain\">index_together\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">[<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">(<\/code><code class=\"python string\">\"pub_date\"<\/code><code class=\"python plain\">,\u00a0<\/code><code class=\"python string\">\"deadline\"<\/code><code class=\"python plain\">),<\/code><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"python plain\">]<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<h3>unique_together<\/h3>\n<p>\u8054\u5408\u552f\u4e00\u7d22\u5f15\uff0c\u4e3a\u4e24\u4e2a\u6216\u591a\u4e2a\u5b57\u6bb5\u5efa\u7acb\u5171\u540c\u7d22\u5f15\uff0c\u5e76\u4e14\u9650\u5236\u4e24\u5217\u8054\u5408\u552f\u4e00<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_329635\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python plain\">unique_together\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">((<\/code><code class=\"python string\">\"driver\"<\/code><code class=\"python plain\">,\u00a0<\/code><code class=\"python string\">\"restaurant\"<\/code><code class=\"python plain\">), )<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<h3>verbose_name<\/h3>\n<p>\u5728admin\u4e2d\u663e\u793a\u7684\u8868\u540d\uff0c\u5728admin\u4e2d\u4f1a\u5728\u8bbe\u7f6e\u7684\u8868\u540d\u540e\u9762\u52a0\u4e0as<\/p>\n<h3>verbose_name_plural<\/h3>\n<p>\u5982\u679c\u5c06\u4e0a\u9762\u7684verbose_name\u8ddfverbose_name_plural\u8bbe\u7f6e\u6210\u540c\u6837\u7684\u503c\uff0c\u5c31\u4e0d\u4f1a\u518dadmin\u4e2d\u663e\u793as<\/p>\n<h2>\u591a\u8868\u5173\u7cfb\u4ee5\u53ca\u53c2\u6570\u7684\u4ecb\u7ecd<\/h2>\n<h3>ForeignKey(ForeignObject)<\/h3>\n<p>ForeignKey\u662f\u8fdb\u884c\u4e00\u5bf9\u591a\u8868\u64cd\u4f5c\u65f6\u7684\u5b57\u6bb5\uff0c\u8bbe\u7f6e\u5728\u591a\u7684\u4e00\u65b9\uff0c\u4e0b\u9762\u5bf9\u8be5\u5b57\u6bb5\u7684\u53c2\u6570\u505a\u8be6\u7ec6\u4ecb\u7ecd<\/p>\n<h4>to<\/h4>\n<p>\u8981\u8fdb\u884c\u5173\u8054\u7684\u8868\u540d\uff0c\u5373\u60f3\u4e0e\u54ea\u5f20\u8868\u8fdb\u884c\u5173\u8054<\/p>\n<div class=\"cnblogs_code\">\n<p><img decoding=\"async\" id=\"code_img_opened_17d9afc1-01dc-4310-a9e4-5df62afa8499\" class=\"code_img_opened mBox\"  src=\"\/wp-content\/uploads\/replace\/961ddebeb323a10fe0623af514929fc1.gif\" alt=\"Python Django Models\u5b57\u6bb5\u8be6\u89e3\" \/><\/p>\n<div id=\"cnblogs_code_open_17d9afc1-01dc-4310-a9e4-5df62afa8499\" class=\"cnblogs_code_hide\">\n<div class=\"cnblogs_code_toolbar\"><\/div>\n<pre>class Husband(models.Model):\r\n    nid = models.AutOField(primary_key=True)\r\n    name = CharField(max_length=32)\r\n\r\n\r\nclass Wives(models.Model):\r\n    name = CharField(max_length=32)\r\n    husband = models.ForeignKey(to='Husband')<\/pre>\n<div class=\"cnblogs_code_toolbar\"><\/div>\n<\/div>\n<\/div>\n<h4>to_field<\/h4>\n<p>\u6307\u5b9a\u8981\u4e0e\u5173\u8054\u7684\u8868\u4e2d\u7684\u54ea\u4e00\u4e2a\u5b57\u6bb5\u8fdb\u884c\u5173\u8054\uff0c\u9ed8\u8ba4\u662f\u548c\u4e3b\u952e\u5173\u8054<\/p>\n<div class=\"cnblogs_code\">\n<p><img decoding=\"async\" id=\"code_img_opened_e9846298-1edc-4ec4-8e0a-68501d768392\" class=\"code_img_opened mBox\"  src=\"\/wp-content\/uploads\/replace\/961ddebeb323a10fe0623af514929fc1.gif\" alt=\"Python Django Models\u5b57\u6bb5\u8be6\u89e3\" \/><\/p>\n<div id=\"cnblogs_code_open_e9846298-1edc-4ec4-8e0a-68501d768392\" class=\"cnblogs_code_hide\">\n<div class=\"cnblogs_code_toolbar\"><\/div>\n<pre>class Husband(models.Model):\r\n    nid = models.AutOField(primary_key=True)\r\n    name = CharField(max_length=32)\r\n\r\n\r\nclass Wives(models.Model):\r\n    name = CharField(max_length=32)\r\n    husband = models.ForeignKey(\r\n        to='Husband',\r\n        to_field='nid',\r\n    )<\/pre>\n<div class=\"cnblogs_code_toolbar\"><\/div>\n<\/div>\n<\/div>\n<h4>on_delete<\/h4>\n<p>\u5f53\u8981\u5220\u9664\u8868\u4e2d\u7684\u67d0\u6761\u8bb0\u5f55\u65f6\uff0c\u600e\u6837\u5904\u7406\u5173\u8054\u8868\u4e2d\u4e0e\u8be5\u6761\u8bb0\u5f55\u5173\u8054\u7684\u8bb0\u5f55<\/p>\n<ul>\n<li>models.CASCADE\uff1a\u5c06\u4e0e\u4e4b\u5173\u8054\u7684\u6570\u636e\u4e00\u8d77\u5220\u9664<\/li>\n<li>models.DO_NOTHING\uff1a\u5f15\u53d1IntegrityErroe\u5f02\u5e38\uff0c\u4e0d\u5141\u8bb8\u5220\u9664\uff0c\u60f3\u8981\u5220\u9664\u5148\u89e3\u9664\u4e0e\u8be5\u8bb0\u5f55\u5173\u8054\u7684\u8bb0\u5f55<\/li>\n<li>models.PROTECT\uff1a\u5f15\u53d1ProtectedError\u5f02\u5e38\uff0c\u4e0d\u5141\u8bb8\u5220\u9664\uff0c\u60f3\u8981\u5220\u9664\u5148\u89e3\u9664\u4e0e\u8be5\u8bb0\u5f55\u5173\u8054\u7684\u8bb0\u5f55<\/li>\n<li>models.SET_NULL\uff1a\u5c06\u4e0e\u4e4b\u5173\u8054\u7684\u8bb0\u5f55\u7684\u5916\u952e\u8bbe\u7f6e\u6210\u7a7a\uff0c\u524d\u63d0\u662f\u5916\u952e\u5141\u8bb8\u4e3a\u7a7a<\/li>\n<li>models.SET_DEFAULT\uff1a\u5c06\u4e0e\u4e4b\u5173\u8054\u7684\u8bb0\u5f55\u7684\u5916\u952e\u8bbe\u7f6e\u6210\u9ed8\u8ba4\u503c\uff0c\u524d\u63d0\u662f\u5916\u952e\u8bbe\u7f6e\u4e86default\u53c2\u6570<\/li>\n<li>models.SET\uff1a\u6709\u4e24\u79cd\u60c5\u51b5\n<ul>\n<li>\u7b2c\u4e00\u79cd\uff0c\u5c06\u4e0e\u4e4b\u5173\u8054\u7684\u8bb0\u5f55\u7684\u5916\u952e\u8bbe\u7f6e\u6210\u6307\u5b9a\u503c\uff0cmodels.SET(\u2018\u6307\u5b9a\u503c\u2019)<\/li>\n<li>\u7b2c\u4e8c\u79cd\uff0c\u5c06\u4e0e\u4e4b\u5173\u8054\u7684\u8bb0\u5f55\u7684\u5916\u952e\u8bbe\u7f6e\u6210\u6307\u5b9a\u53ef\u6267\u884c\u5bf9\u8c61\u7684\u8fd4\u56de\u503c\uff0c\u5373\u5982\u4e0b\u6240\u793a\uff1a<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<div class=\"cnblogs_code\">\n<p><img decoding=\"async\" id=\"code_img_opened_864766f0-a0ca-4103-8813-8a11732afedb\" class=\"code_img_opened mBox\"  src=\"\/wp-content\/uploads\/replace\/961ddebeb323a10fe0623af514929fc1.gif\" alt=\"Python Django Models\u5b57\u6bb5\u8be6\u89e3\" \/><\/p>\n<div id=\"cnblogs_code_open_864766f0-a0ca-4103-8813-8a11732afedb\" class=\"cnblogs_code_hide\">\n<div class=\"cnblogs_code_toolbar\"><\/div>\n<pre>def func():\r\n    return 10\r\n\r\n\r\nclass MyModels(models.Model)\r\n    fk = models.ForeignKey(\r\n        to='User', \r\n        to_field='id', \r\n        on_delete=models.SET(func(), )\r\n    )<\/pre>\n<div class=\"cnblogs_code_toolbar\"><\/div>\n<\/div>\n<\/div>\n<h4>related_name<\/h4>\n<p>\u53cd\u5411\u64cd\u4f5c\u65f6\uff0c\u4f7f\u7528\u7684\u5b57\u6bb5\u540d\uff0c\u6ca1\u6709\u8bbe\u7f6e\u65f6\u9ed8\u8ba4\u4e3a\u3010\u8868\u540d_set\u3011<\/p>\n<p>\u4f8b\u5982\uff1a<\/p>\n<p>obj.book_set.all()<\/p>\n<p>\u5982\u679c\u8bbe\u7f6e\u4e86related_name\u4e3a\"book\"\uff0c\u90a3\u4e48\u53cd\u5411\u67e5\u8be2\u53d8\u6210\u4e86\uff1a<\/p>\n<p>obj.book.all()<\/p>\n<h4>related_query_name<\/h4>\n<p>\u53cd\u5411\u64cd\u4f5c\u65f6\u4f7f\u7528\u7684\u540d\u79f0\uff0c\u4e0d\u8fc7\u8fd9\u4e2a\u53ea\u662f\u66ff\u6362\u4e86\u8868\u540d\uff0c\u5e76\u6ca1\u6709\u66ff\u6362\u6389set<\/p>\n<p>\u4f8b\u5982\uff1a<\/p>\n<p>obj.book_set.all()<\/p>\n<p>\u5982\u679c\u8bbe\u7f6e\u4e86related_query_name\u4e3a\"bk\"\uff0c\u90a3\u4e48\u53cd\u5411\u67e5\u8be2\u53d8\u6210\u4e86\uff1a<\/p>\n<p>obj.bk_set.all()<\/p>\n<h4>limit_choices_to<\/h4>\n<p>\u5728Admin\u6216\u8005ModelForm\u4e2d\u663e\u793a\u6570\u636e\u65f6\uff0c\u63d0\u4f9b\u7684\u6761\u4ef6<\/p>\n<p>\u4f8b\u5982\uff1a<\/p>\n<p><span class=\"cnblogs_code\">limit_choices_to={'id_gt': 5}<\/span>\u00a0\u5c31\u53ea\u4f1a\u663e\u793aid\u5927\u4e8e5\u7684\u4fe1\u606f<\/p>\n<p><span class=\"cnblogs_code\">limit_choices_to=Q(id__gt=8) | Q(id__lt=20)<\/span>\u00a0\u5c31\u53ea\u4f1a\u663e\u793aid\u5927\u4e8e8\u5c0f\u4e8e20\u7684\u4fe1\u606f<\/p>\n<h4>db_constraint<\/h4>\n<p>\u662f\u5426\u5728\u6570\u636e\u5e93\u4e2d\u521b\u5efa\u5916\u952e\u7ea6\u675f\uff0c\u672c\u6765\u5f53ForeignKey\u5173\u8054\u4e86\u67d0\u5f20\u8868\u540e\uff0c\u90a3\u4e48\u5916\u952e\u5c31\u53ea\u80fd\u662f\u54ea\u5f20\u8868\u7684id\u4e2d\u51fa\u73b0\u7684\u503c\u4e86\uff0c\u4f46\u662f\u5982\u679c\u8bbe\u7f6e\u4e86db_constraint\u4e3aTrue\u540e\u5c31\u53ef\u4ee5\u5c06\u5916\u952e\u8bbe\u7f6e\u6210\u5173\u8054\u8868id\u4ee5\u5916\u7684\u503c\u4e86\uff0c\u5173\u8054\u8868\u5c06\u5bf9\u8be5\u8868\u6ca1\u6709\u4efb\u4f55\u7ea6\u675f<\/p>\n<h4>parent_link<\/h4>\n<p>\u5728Admin\u4e2d\u662f\u5426\u663e\u793a\u5173\u8054\u6570\u636e<\/p>\n<h3>OneToOneField(ForeignKey)<\/h3>\n<p>\u4e24\u5f20\u8868\u7684\u4e00\u5bf9\u4e00\u5173\u7cfb\u5b9e\u9645\u4e0a\u662f\u901a\u8fc7 \u4e00\u5bf9\u591a+unique \u6765\u5b9e\u73b0\u7684\uff0c\u5728\u4e00\u5bf9\u591a\u7684\u57fa\u7840\u4e0a\u8ba9\u5916\u952e\u53ea\u80fd\u662f\u552f\u4e00\u7684\uff0c\u90a3\u6837\u4e0d\u5c31\u505a\u5230\u4e00\u5bf9\u4e00\u4e86\u5417\uff0c\u4e0b\u9762\u5bf9\u4e00\u5bf9\u4e00\u7684\u53c2\u6570\u8fdb\u884c\u4ecb\u7ecd<\/p>\n<h4>to<\/h4>\n<p>\u8981\u8fdb\u884c\u5173\u8054\u7684\u8868\u540d<\/p>\n<h4>to_field<\/h4>\n<p>\u9009\u62e9\u4e0e\u5173\u8054\u8868\u7684\u54ea\u4e00\u5217\u8fdb\u884c\u5173\u8054<\/p>\n<h4>on_delete<\/h4>\n<p>\u9009\u62e9\u5bf9\u5173\u8054\u6570\u636e\u7684\u5904\u7406\u65b9\u5f0f\uff0c\u4e0e\u4e00\u5bf9\u591a\u4e00\u81f4<\/p>\n<h3>ManyToManyField(RelatedField)<\/h3>\n<p>\u4e24\u5f20\u8868\u8fdb\u884c\u591a\u5bf9\u591a\u5173\u8054\u65f6\u4f1a\u4f7f\u7528\u8be5\u5b57\u6bb5\uff0c\u81f3\u4e8e\u8be5\u5b57\u6bb5\u51fa\u73b0\u5728\u54ea\u5f20\u8868\u65e0\u6240\u8c13\uff0c\u4e0b\u9762\u5bf9\u8be5\u5b57\u6bb5\u7684\u53c2\u6570\u505a\u4ecb\u7ecd<\/p>\n<h4>to<\/h4>\n<p>\u8981\u8fdb\u884c\u5173\u8054\u7684\u8868\u540d<\/p>\n<h4>related_name<\/h4>\n<p>\u53cd\u5411\u64cd\u4f5c\u65f6\uff0c\u4f7f\u7528\u7684\u5b57\u6bb5\u540d\uff0c\u4ee3\u66ff\u3010\u8868\u540d_set\u3011\uff0c\u5177\u4f53\u7528\u6cd5\u4e0e\u4e00\u5bf9\u591a\u4e2d\u7684\u4e00\u81f4<\/p>\n<h4>related_query_name<\/h4>\n<p>\u53cd\u5411\u64cd\u4f5c\u65f6\u7528\u4e8e\u4ee3\u66ff\u3010\u8868\u540d\u3011\uff0c\u5177\u4f53\u7528\u6cd5\u4e0e\u4e00\u5bf9\u591a\u4e2d\u4e00\u81f4<\/p>\n<h4>limit_choices_to<\/h4>\n<p>\u5728Admin\u6216\u8005ModelForm\u4e2d\u663e\u793a\u6570\u636e\u65f6\uff0c\u63d0\u4f9b\u7684\u6761\u4ef6\uff0c\u5177\u4f53\u7528\u6cd5\u4e0e\u4e00\u5bf9\u591a\u4e2d\u4e00\u81f4<\/p>\n<h4>symmetrical<\/h4>\n<p>\u4ec5\u7528\u4e8e\u591a\u5bf9\u591a\u81ea\u5173\u8054\u65f6\uff0csymmetrical\u7528\u4e8e\u6307\u5b9a\u5185\u90e8\u662f\u5426\u521b\u5efa\u53cd\u5411\u64cd\u4f5c\u7684\u5b57\u6bb5<\/p>\n<p>\u5982\u4e0b\uff0c\u5728\u505a\u81ea\u5173\u8054\u65f6\uff0csymmetrical\u8bbe\u7f6e\u6210True\u8ddfFalse\u4f1a\u6709\u4e0d\u540c\u7684\u5b57\u6bb5\u53ef\u9009<\/p>\n<p>\u505a\u00a0<span class=\"cnblogs_code\">models.BB.objects.filter(...)<\/span>\u00a0\u64cd\u4f5c<\/p>\n<p>\u8bbe\u7f6e\u6210True\u53ef\u9009\u5b57\u6bb5\u4e3acode\uff0cid\uff0cm1<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_938468\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<div class=\"line number2 index1 alt1\">2<\/div>\n<div class=\"line number3 index2 alt2\">3<\/div>\n<div class=\"line number4 index3 alt1\">4<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python keyword\">class<\/code>\u00a0<code class=\"python plain\">BB(models.Model):<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">code\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.CharField(max_length<\/code><code class=\"python keyword\">=<\/code><code class=\"python value\">12<\/code><code class=\"python plain\">)<\/code><\/div>\n<div class=\"line number4 index3 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">m1\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.ManyToManyField(<\/code><code class=\"python string\">'self'<\/code><code class=\"python plain\">,symmetrical<\/code><code class=\"python keyword\">=<\/code><code class=\"python color1\">True<\/code><code class=\"python plain\">)<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<p>\u8bbe\u7f6e\u6210True\u53ef\u9009\u5b57\u6bb5\u4e3acode\uff0cid\uff0cm1\uff0cbb<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_814183\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<div class=\"line number2 index1 alt1\">2<\/div>\n<div class=\"line number3 index2 alt2\">3<\/div>\n<div class=\"line number4 index3 alt1\">4<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python keyword\">class<\/code>\u00a0<code class=\"python plain\">BB(models.Model):<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">code\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.CharField(max_length<\/code><code class=\"python keyword\">=<\/code><code class=\"python value\">12<\/code><code class=\"python plain\">)<\/code><\/div>\n<div class=\"line number4 index3 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">m1\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.ManyToManyField(<\/code><code class=\"python string\">'self'<\/code><code class=\"python plain\">,symmetrical<\/code><code class=\"python keyword\">=<\/code><code class=\"python color1\">False<\/code><code class=\"python plain\">)<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<h4>db_constraint<\/h4>\n<p>\u662f\u5426\u5728\u6570\u636e\u5e93\u4e2d\u521b\u5efa\u5916\u952e\u7ea6\u675f\uff0c\u4e0e\u4e00\u5bf9\u591a\u7684db_constraint\u4e00\u81f4<\/p>\n<h4>db_table<\/h4>\n<p>\u5728\u521b\u5efa\u7b2c\u4e09\u5f20\u8868\u65f6\uff0c\u4e3a\u7b2c\u4e09\u5f20\u8868\u53d6\u7684\u540d\u5b57\uff0c\u5982\u679c\u6ca1\u6709\u8bbe\u7f6e\u5219\u9ed8\u8ba4\u4f7f\u7528\u4e0b\u5212\u7ebf\u5c06\u591a\u5bf9\u591a\u7684\u4e24\u5f20\u8868\u7684\u8868\u540d\u8fde\u8d77\u6765\u4f5c\u4e3a\u7b2c\u4e09\u5f20\u8868\u7684\u8868\u540d<\/p>\n<h4>through<\/h4>\n<p>\u81ea\u5b9a\u4e49\u7b2c\u4e09\u5f20\u8868\u65f6\uff0c\u7b2c\u4e09\u5f20\u8868\u7684\u8868\u540d<\/p>\n<h4>through_fields<\/h4>\n<p>\u81ea\u5b9a\u4e49\u7b2c\u4e09\u5f20\u8868\u65f6\uff0c\u7b2c\u4e09\u5f20\u8868\u4e2d\u53ef\u80fd\u6709\u5f88\u591a\u5b57\u6bb5\u4e0e\u591a\u5bf9\u591a\u7684\u4e24\u5f20\u8868\u8fdb\u884c\u5916\u952e\u5173\u8054\uff0c\u4f7f\u7528through_fields\u53ef\u4ee5\u6307\u5b9a\u90a3\u4e24\u4e2a\u5b57\u6bb5\u4e3a\u8054\u7cfb\u4e24\u5f20\u8868\u7684\u5916\u952e<\/p>\n<p>\u5982\uff1a\u00a0<span class=\"cnblogs_code\">through_fields=('group',\u00a0'person')<\/span><\/p>\n<h3>\u591a\u5bf9\u591a\u521b\u5efa\u7b2c\u4e09\u5f20\u8868<\/h3>\n<p>\u5728\u591a\u5bf9\u591a\u5173\u7cfb\u4e2d\uff0c\u9664\u4e86\u8fdb\u884c\u591a\u5bf9\u591a\u5173\u8054\u7684\u4e24\u5f20\u8868\u4ee5\u5916\uff0c\u8fd8\u4f1a\u6709\u7b2c\u4e09\u5f20\u8868\uff0c\u90a3\u4e48\u7b2c\u4e09\u5f20\u8868\u600e\u6837\u521b\u5efa\u5462\uff1f\u4e0b\u9762\u4ecb\u7ecd\u4e09\u79cd\u65b9\u5f0f<\/p>\n<h4>\u81ea\u52a8\u521b\u5efa<\/h4>\n<p>\u7b2c\u4e00\u79cd\u65b9\u5f0f\u53ef\u4ee5\u4f7f\u7528ManyToManyField\u5b57\u6bb5\u81ea\u52a8\u521b\u5efa\u7b2c\u4e09\u5f20\u8868<\/p>\n<h4>\u624b\u52a8\u521b\u5efa<\/h4>\n<p>\u4f7f\u7528\u7b2c\u4e00\u79cd\u65b9\u5f0f\u81ea\u52a8\u521b\u5efa\u786e\u5b9e\u5f88\u65b9\u4fbf\uff0c\u4f46\u662f\u5982\u679c\u60f3\u5728\u7b2c\u4e09\u5f20\u8868\u4e2d\u6dfb\u52a0\u66f4\u591a\u7684\u5b57\u6bb5\u5e94\u8be5\u600e\u4e48\u529e\u5462\uff1f\u663e\u7136\u81ea\u52a8\u521b\u5efa\u662f\u4e0d\u884c\u7684\u4e86\uff0c\u81ea\u52a8\u521b\u5efa\u53ea\u80fd\u521b\u5efa\u4e09\u884c\u6570\u636e\uff0c\u4e00\u4e2a\u662f\u81ea\u5df1\u7684id\uff0c\u5176\u4f59\u4e24\u4e2a\u662f\u4e0e\u4e24\u5f20\u8868\u5173\u8054\u7684\u5916\u952e\uff0c\u5982\u679c\u8fd9\u65f6\u9700\u8981\u6dfb\u52a0\u66f4\u591a\u7684\u5b57\u6bb5\u5c31\u9700\u8981\u81ea\u5df1\u5b9a\u4e49\u7b2c\u4e09\u5f20\u8868\u4e86\uff0c\u5728\u7b2c\u4e09\u5f20\u8868\u4e2d\u9996\u5148\u9700\u8981\u521b\u5efa\u7684\u662f\u4e24\u4e2a\u5916\u952e\u5206\u522b\u5173\u8054\u591a\u5bf9\u591a\u7684\u4e24\u5f20\u8868\uff0c\u8fd9\u6837\u5c31\u5c06\u4e24\u5f20\u8868\u8054\u7cfb\u8d77\u6765\u4e86\uff0c\u4f46\u662f\u8fd9\u6837\u8fd8\u4e0d\u591f\uff0c\u56e0\u4e3a\u5982\u679c\u53ea\u662f\u8fd9\u6837\uff0c\u90a3\u4e48\u7b2c\u4e09\u5f20\u8868\u4e2d\u7684\u4e24\u4e2a\u5916\u952e\u53ef\u4ee5\u5728\u6dfb\u52a0\u4e861\u8ddf1\u540e\uff0c\u6309\u7406\u662f\u4e0d\u80fd\u518d\u6dfb\u52a01\u8ddf1\u4e86\u7684\uff0c\u4f46\u662f\u5982\u679c\u6211\u4eec\u53ea\u662f\u521b\u5efa\u4e86\u4e24\u4e2a\u5916\u952e\u6ca1\u6709\u505a\u5176\u4ed6\u7684\u64cd\u4f5c\uff0c\u90a3\u4e48\u5728\u6dfb\u52a01\u8ddf1\u540e\u786e\u5b9e\u8fd8\u80fd\u518d\u6dfb\u52a01\u8ddf1\uff0c\u90a3\u8fd9\u6837\u663e\u7136\u4e0d\u884c\uff0c\u56e0\u6b64\u8fd8\u5e94\u8be5\u7ed9\u8fd9\u4e24\u4e2a\u5916\u952e\u52a0\u4e0a\u8054\u5408\u552f\u4e00\u624d\u884c\uff0c\u56e0\u6b64\u6700\u7ec8\u7b2c\u4e09\u5f20\u8868\u5c31\u662f\u8fd9\u6837\u7684\uff1a<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_571080\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<div class=\"line number2 index1 alt1\">2<\/div>\n<div class=\"line number3 index2 alt2\">3<\/div>\n<div class=\"line number4 index3 alt1\">4<\/div>\n<div class=\"line number5 index4 alt2\">5<\/div>\n<div class=\"line number6 index5 alt1\">6<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python keyword\">class<\/code>\u00a0<code class=\"python plain\">UserToTag(models.Model):<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">u\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.ForeignKey(to<\/code><code class=\"python keyword\">=<\/code><code class=\"python string\">\"User\"<\/code><code class=\"python plain\">)<\/code><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">t\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.ForeignKey(to<\/code><code class=\"python keyword\">=<\/code><code class=\"python string\">\"Tag\"<\/code><code class=\"python plain\">)<\/code><\/div>\n<div class=\"line number4 index3 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><\/div>\n<div class=\"line number5 index4 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python keyword\">class<\/code>\u00a0<code class=\"python plain\">Meta:<\/code><\/div>\n<div class=\"line number6 index5 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python plain\">unique_together((<\/code><code class=\"python string\">'u'<\/code><code class=\"python plain\">,\u00a0<\/code><code class=\"python string\">'t'<\/code><code class=\"python plain\">), )<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<h4>\u624b\u52a8+\u81ea\u52a8<\/h4>\n<p>\u9664\u4e86\u4f7f\u7528ManyToManyField\u521b\u5efa\u4ee5\u53ca\u81ea\u5df1\u624b\u52a8\u521b\u5efa\u4ee5\u5916\u8fd8\u80fd\u901a\u8fc7ManyToManyField\u5b57\u6bb5+\u624b\u52a8\u6765\u4e00\u8d77\u521b\u5efa\u7b2c\u4e09\u5f20\u8868\uff0c\u8fd9\u65f6\u4fbf\u8981\u4f7f\u7528\u5230\u00a0<span class=\"cnblogs_code\">through<\/span>\u00a0\u8ddf\u00a0<span class=\"cnblogs_code\">through_fields<\/span>\u00a0\u6765\u5728ManyToManyField\u4e2d\u53bb\u6307\u5b9a\u7b2c\u4e09\u5f20\u8868\u4e86\uff0c\u4e0d\u8fc7\u8fd9\u65f6add\uff0cremove\u7b49\u65b9\u6cd5\u90fd\u4f1a\u5931\u6548\uff0c\u56e0\u6b64\u4e0d\u5efa\u8bae\u4f7f\u7528\u7b2c\u4e09\u79cd\u65b9\u6cd5\u521b\u5efa\u7b2c\u4e09\u5f20\u8868<\/p>\n<h2>QuerySet\u53c2\u6570\u8be6\u89e3<\/h2>\n<div class=\"table-wrapper\">\n<table border=\"0\" align=\"left\">\n<tbody>\n<tr>\n<td><strong>\u65b9\u6cd5<\/strong><\/td>\n<td><strong>\u8bf4\u660e<\/strong><\/td>\n<td><strong>\u6f14\u793a<\/strong><\/td>\n<td><strong>\u6f14\u793a\u8bf4\u660e<\/strong><\/td>\n<\/tr>\n<tr>\n<td>all<\/td>\n<td>\u67e5\u8be2\u6240\u6709\u7684\u8bb0\u5f55<\/td>\n<td>Book.objects.all()<\/td>\n<td>\u53ef\u4ee5\u67e5\u51fa\u4e66\u7c4d\u8868\u4e2d\u7684\u6bcf\u4e00\u5217\u6570\u636e<\/td>\n<\/tr>\n<tr>\n<td>first<\/td>\n<td>\u62ff\u5230\u7b2c\u4e00\u6761\u8bb0\u5f55<\/td>\n<td>Book.objects.first()<\/td>\n<td>\u62ff\u5230\u4e66\u7c4d\u8868\u4e2d\u7684\u7b2c\u4e00\u6761\u8bb0\u5f55<\/td>\n<\/tr>\n<tr>\n<td>last<\/td>\n<td>\u62ff\u5230\u6700\u540e\u4e00\u6761\u8bb0\u5f55<\/td>\n<td>Book.objects.last()<\/td>\n<td>\u62ff\u5230\u4e66\u7c4d\u8868\u4e2d\u7684\u6700\u540e\u4e00\u6761\u8bb0\u5f55<\/td>\n<\/tr>\n<tr>\n<td>get<\/td>\n<td>\u62ff\u5230\u7b26\u5408\u6761\u4ef6\u7684\u6570\u636e\uff0c\u53ea\u6709\u4e00\u6761\u6570\u636e,\u800c\u4e14\u53ea\u6709\u7ed3\u679c\u662f\u4e00\u6761\u6570\u636e\u65f6\u624d\u6ca1\u95ee\u9898\uff0c<\/p>\n<p>\u5982\u679c\u67e5\u8be2\u7ed3\u679c\u662f\u591a\u6761\u6570\u636e\u6216\u8005\u662f0\u7684\u8bdd\u5c31\u4f1a\u62a5\u9519<\/td>\n<td>Book.objects.get(**kwargs)<\/td>\n<td>\u8fd9\u91cc\u62ff\u5230\u7684\u662f\u4e00\u4e2abook\u5bf9\u8c61\uff0c\u67e5\u8be2\u7684\u5185\u5bb9\u4e5f\u53ef\u4ee5\u662f\u67d0\u4e2a\u5355\u4e00\u7684\u5b57\u6bb5\uff0c<\/p>\n<p>\u4f8b\u5982\uff1aBook.objects.get(id=3)<\/td>\n<\/tr>\n<tr>\n<td>values<\/td>\n<td>\u83b7\u53d6\u67e5\u8be2\u5bf9\u8c61\u4e2d\u7684\u67d0\u4e2a\u6216\u67d0\u51e0\u4e2a\u5b57\u6bb5(\u4ee5\u5b57\u5178\u7684\u5f62\u5f0f\u5c55\u793a)<\/td>\n<td>Book.objects.filter(name=\"python\u57fa\u7840\").values(\"price\", \"pub_date\")<\/td>\n<td>\u62ff\u5230\u7684\u662f\u6240\u6709\u540d\u5b57\u4e3apython\u57fa\u7840\u7684\u4e66\u7c4d\u7684\u4ef7\u683c\u548c\u51fa\u7248\u65e5\u671f<\/td>\n<\/tr>\n<tr>\n<td>values_list<\/td>\n<td>\u83b7\u53d6\u67e5\u8be2\u5bf9\u8c61\u4e2d\u7684\u67d0\u4e2a\u6216\u67d0\u51e0\u4e2a\u5b57\u6bb5(\u4ee5\u5217\u8868\u7684\u5f62\u5f0f\u5c55\u793a)<\/td>\n<td>Book.objects.filter(name=\"python\u57fa\u7840\").values_list(\"price\", \"pub_date\")<\/td>\n<td>\u4e0e\u4e0a\u9762\u76f8\u540c\uff0c\u53ea\u662f\u5c06\u6570\u636e\u90fd\u5b58\u5230\u4e86\u5217\u8868\u4e2d\uff0c\u6bcf\u4e00\u5217\u7684\u6570\u636e\u5355\u72ec\u4ee5\u4e00\u4e2a\u5143\u7ec4\u50a8\u5b58<\/td>\n<\/tr>\n<tr>\n<td>distinct<\/td>\n<td>\u53bb\u6389\u67d0\u5b57\u6bb5\u91cd\u590d\u7684\u9879<\/td>\n<td>Book.objects.all().value(\"name\").distinct()<\/td>\n<td>\u53ea\u6709\u5728\u5bf9\u67d0\u5b57\u6bb5\u53bb\u91cd\u65f6\u624d\u6709\u610f\u4e49\uff0c\u56e0\u4e3a\u5bf9\u4e8e\u6574\u6761\u8bb0\u5f55\u800c\u8a00\uff0c\u7531\u4e8e\u6709\u4e3b\u952eid\u7684\u5b58\u5728\uff0c\u6240\u4ee5\u4e0d\u53ef\u80fd\u6709\u91cd\u590d\u7684\u9879\uff0c\u6240\u4ee5\u5bf9\u6574\u6761\u8bb0\u5f55\u8fdb\u884c\u53bb\u91cd\u662f\u6ca1\u6709\u610f\u4e49\u7684<\/td>\n<\/tr>\n<tr>\n<td>count<\/td>\n<td>\u8ba1\u6570<\/td>\n<td>Book.objects.all().count()<\/td>\n<td>\u8ba1\u7b97\u67e5\u5230\u7684QuerySet\u96c6\u5408\u7684\u957f\u5ea6<\/td>\n<\/tr>\n<tr>\n<td>filter<\/td>\n<td>\u6309\u7167\u6761\u4ef6\u8fdb\u884c\u67e5\u627e<\/td>\n<td>Book.objects.filter(name=\"python\u57fa\u7840\")<\/td>\n<td>\u4e0eget()\u65b9\u6cd5\u4e0d\u540c\uff0c\u8fd9\u4e2a\u53ef\u4ee5\u67e5\u8be2\u591a\u6761\u8bb0\u5f55<\/td>\n<\/tr>\n<tr>\n<td>exclude<\/td>\n<td>\u67e5\u8be2\u51fa\u6761\u4ef6\u4ee5\u5916\u7684\u6570\u636e<\/td>\n<td>Book.objects.exclude(name=\"python\u57fa\u7840\")<\/td>\n<td>\u67e5\u8be2\u51fa\u540d\u5b57\u4e0d\u4e3a python\u57fa\u7840\u7684\u4e66\u7c4d<\/td>\n<\/tr>\n<tr>\n<td>order_by<\/td>\n<td>\u5c06\u67e5\u8be2\u7684\u7ed3\u679c\u6309\u7167\u67d0\u5217\u8fdb\u884c\u5347\u5e8f\u6216\u964d\u5e8f\u6392\u5217<\/td>\n<td>\n<pre>models.Tb1.objects.filter(name='seven').order_by('id')<\/pre>\n<pre>models.Tb1.objects.filter(name='seven').order_by('-id')<\/pre>\n<\/td>\n<td>\u00a0\u4f7f\u7528id\u4e3a\u5347\u5e8f\uff0c\u4f7f\u7528-id\u4e3a\u964d\u5e8f<\/td>\n<\/tr>\n<tr>\n<td>reverse<\/td>\n<td>\u5012\u5e8f\uff0c\u5bf9order_by()\u540e\u7684\u6570\u636e\u6709\u6548<\/td>\n<td>\n<pre>models.UserInfo.objects.all().order_by('-nid').reverse()<\/pre>\n<\/td>\n<td>\u5982\u679c\u5b58\u5728order_by()\uff0creverse\u662f\u5012\u5e8f\uff0c\u5982\u679c\u662f\u591a\u4e2a\u6392\u5e8f\u5219\u4e00\u4e00\u5012\u5e8f<\/td>\n<\/tr>\n<tr>\n<td>defer<\/td>\n<td>\u4e0d\u53d6\u67d0\u51e0\u5217\u6570\u636e<\/td>\n<td>\n<pre>models.UserInfo.objects.filter(...).defer('username','id')<\/pre>\n<\/td>\n<td>\u00a0\u4e0d\u53d6username\u8ddfid\u5217<\/td>\n<\/tr>\n<tr>\n<td>only<\/td>\n<td>\u53ea\u53d6\u67d0\u51e0\u5217\u6570\u636e<\/td>\n<td>\n<pre>models.UserInfo.objects.only('username','id')<\/pre>\n<\/td>\n<td>\u53ea\u53d6username\u8ddfid\u5217\uff0c\u76f8\u5f53\u4e8eSELECT username, id FROM UserInfo<\/td>\n<\/tr>\n<tr>\n<td>using<\/td>\n<td>\u6307\u5b9a\u8981\u4f7f\u7528\u7684\u6570\u636e\u5e93\uff0c\u53c2\u6570\u662f\u522b\u540d(\u5728settings.py\u7684DATABASES\u5b57\u5178\u4e2d\u914d\u7f6e\u7684\u540d\u5b57)<\/td>\n<td>\u00a0<img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-83 mBox\"  src=\"http:\/\/idc.birk.cn\/wp-content\/uploads\/2023\/03\/1321729-20180801190640262-480039588.png\" alt=\"Python Django Models\u5b57\u6bb5\u8be6\u89e3\" width=\"673\" height=\"229\" srcset=\"https:\/\/idc.birk.cn\/wp-content\/uploads\/2023\/03\/1321729-20180801190640262-480039588.png 673w, https:\/\/idc.birk.cn\/wp-content\/uploads\/2023\/03\/1321729-20180801190640262-480039588-300x102.png 300w\" sizes=\"auto, (max-width: 673px) 100vw, 673px\" \/><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>dates<\/td>\n<td>\u6839\u636e\u65f6\u95f4\u8fdb\u884c\u67d0\u4e00\u90e8\u5206\u7684\u53bb\u91cd\u67e5\u627e\u5e76\u622a\u53d6\u6307\u5b9a\u5185\u5bb9<\/td>\n<td>\n<pre>models.DatePlus.objects.dates('ctime','day','DESC')<\/pre>\n<\/td>\n<td>\u53c2\u6570\u8bf4\u660e\uff1a<\/p>\n<p>field_name\uff1a\u8981\u7b5b\u9009\u7684\u5b57\u6bb5\u540d<\/p>\n<p>kind\uff1a\u53ea\u80fd\u662f\"year\" \"month\" \"day\"<\/p>\n<p>order\u53ea\u80fd\u662f\"ASC\" \"DESC\"<\/p>\n<p>\u5e76\u83b7\u53d6\u8f6c\u6362\u540e\u7684\u65f6\u95f4<\/p>\n<p>year\uff1a\u5e74-01-01<\/p>\n<p>month\uff1a\u5e74-\u6708-01<\/p>\n<p>day\uff1a\u5e74-\u6708-\u65e5<\/td>\n<\/tr>\n<tr>\n<td>datetimes<\/td>\n<td>\u6839\u636e\u65f6\u95f4\u8fdb\u884c\u67d0\u4e00\u90e8\u5206\u7684\u53bb\u91cd\u67e5\u627e\u5e76\u622a\u53d6\u6307\u5b9a\u5185\u5bb9\uff0c\u5c06\u65f6\u95f4\u8f6c\u6362\u6210\u6307\u5b9a\u65f6\u533a\u7684\u65f6\u95f4<\/td>\n<td>\n<pre>models.DDD.objects.datetimes('ctime','hour',tzinfo=pytz.UTC)\r\nmodels.DDD.objects.datetimes('ctime','hour',tzinfo=pytz.timezone('Asia\/Shanghai'))\r\n\r\n<\/pre>\n<pre>pip3 install pytz\r\nimport pytz\r\npytz.all_timezones\r\npytz.timezone(\u2018Asia\/Shanghai\u2019)<\/pre>\n<\/td>\n<td>\u53c2\u6570\u8bf4\u660e\uff1a<\/p>\n<p>field_name\uff1a\u8981\u7b5b\u9009\u7684\u5b57\u6bb5\u540d<\/p>\n<p>kind\uff1a\u53ea\u80fd\u662f\"year\" \"month\" \"day\" \"hour\" \"minute\" \"second\"<\/p>\n<p>order\u53ea\u80fd\u662f\"ASC\" \"DESC\"<\/p>\n<p>tzinfo\uff1a\u65f6\u533a\u5bf9\u8c61<\/td>\n<\/tr>\n<tr>\n<td>\u00a0none<\/td>\n<td>\u00a0\u7a7aQuerySet\u5bf9\u8c61<\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>bulk_create<\/td>\n<td>\u6279\u91cf\u63d2\u5165<\/td>\n<td>\n<pre>objs = [\r\n    models.DDD(name='r11'),\r\n    models.DDD(name='r22')\r\n]\r\nmodels.DDD.objects.bulk_create(objs, 10)<\/pre>\n<\/td>\n<td>\u540e\u9762\u768410\u8868\u65f6\u6bcf\u63d2\u516510\u6761\u6570\u636e\u5411\u6570\u636e\u5e93\u63d0\u4ea4\u4e00\u6b21<\/td>\n<\/tr>\n<tr>\n<td>get_or_create<\/td>\n<td>\u5982\u679c\u5b58\u5728\u5219\u83b7\u53d6\uff0c\u5426\u5219\u521b\u5efa<\/td>\n<td>\n<pre>obj, created = models.UserInfo.objects.get_or_create(username='root1', defaults={'email': '1111111','u_id': 2, 't_id': 2})<\/pre>\n<\/td>\n<td>\u00a0\u5982\u679c\u5b58\u5728username\u7b49\u4e8eroot1\u5219\u53d6\u51fa\uff0c\u5426\u5219\u521b\u5efaroot1,\u5e76\u4e14\u5176\u4ed6\u5b57\u6bb5\u662fdefaults\u91cc\u9762\u7684\u5185\u5bb9<\/td>\n<\/tr>\n<tr>\n<td>update_or_create<\/td>\n<td>\u5982\u679c\u5b58\u5728\u5c31\u66f4\u65b0\uff0c\u5426\u5219\u521b\u5efa<\/td>\n<td>\n<pre>obj, created = models.UserInfo.objects.update_or_create(username='root1', defaults={'email': '1111111','u_id': 2, 't_id': 1})<\/pre>\n<\/td>\n<td>\u00a0\u5982\u679c\u5b58\u5728username\u7b49\u4e8eroot1\u5219\u5c06defaults\u91cc\u9762\u7684\u5185\u5bb9\u66f4\u65b0\u8fdb\u53bb\uff0c\u5426\u5219\u521b\u5efaroot1,\u5e76\u4e14\u5176\u4ed6\u5b57\u6bb5\u662fdefaults\u91cc\u9762\u7684\u5185\u5bb9<\/td>\n<\/tr>\n<tr>\n<td>in_bulk<\/td>\n<td>\u6839\u636e\u4e3b\u952eID\u8fdb\u884c\u67e5\u627e<\/td>\n<td>\n<pre>id_list = [11,21,31]\r\nmodels.DDD.objects.in_bulk(id_list)<\/pre>\n<\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>delete<\/td>\n<td>\u5220\u9664<\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>update<\/td>\n<td>\u66f4\u65b0<\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>exists<\/td>\n<td>\u662f\u5426\u6709\u7ed3\u679c<\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td>create<\/td>\n<td>\u63d2\u5165\u4e00\u6761\u8bb0\u5f55<\/td>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>&nbsp;<\/p>\n<h2>\u81ea\u5df1\u5199\u539f\u751fSQL<\/h2>\n<p>\u5728Django\u4e2d\uff0c\u5df2\u7ecf\u7ed9\u5b9a\u7684\u64cd\u4f5c\u5df2\u7ecf\u80fd\u591f\u5f886\u7684\u64cd\u4f5c\u6570\u636e\u5e93\u4e86\uff0c\u4f46\u662f\u5982\u679c\u4ecd\u65e7\u89c9\u5f97\u4e0d\u591f\uff0c\u90a3\u4e48\u4e5f\u53ef\u4ee5\u81ea\u5df1\u5199SQL\u8bed\u53e5\u53bb\u6267\u884c\uff0c\u81ea\u5df1\u5199SQL\u53bb\u6267\u884c\u7684\u65b9\u5f0f\u6709\u4e09\u79cd\uff0c\u4e0b\u9762\u4e00\u4e00\u4ecb\u7ecd<\/p>\n<h3>\u4f7f\u7528connection<\/h3>\n<p>\u7b2c\u4e00\u79cd\u65b9\u5f0f\u53ef\u4ee5\u7528connection\u6765\u505a\u4e5f\u53ef\u4ee5\u7528connections\u505a\uff0c\u5728\u7528connections\u505a\u7684\u65f6\u5019\uff0c\u53ef\u4ee5\u6307\u5b9a\u53bb\u54ea\u4e2a\u6570\u636e\u5e93\u64cd\u4f5c\uff0c\u800c\u540d\u5b57\u662f\u5728settings.py\u4e2d\u5df2\u7ecf\u914d\u7f6e\u597d\u4e86\u7684\u6570\u636e\u5e93\uff0c\u5982\u4e0b\uff1a<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-84 mBox\"  src=\"http:\/\/idc.birk.cn\/wp-content\/uploads\/2023\/03\/1321729-20180801190723354-1947020971.png\" alt=\"Python Django Models\u5b57\u6bb5\u8be6\u89e3\" width=\"673\" height=\"229\" srcset=\"https:\/\/idc.birk.cn\/wp-content\/uploads\/2023\/03\/1321729-20180801190723354-1947020971.png 673w, https:\/\/idc.birk.cn\/wp-content\/uploads\/2023\/03\/1321729-20180801190723354-1947020971-300x102.png 300w\" sizes=\"auto, (max-width: 673px) 100vw, 673px\" \/><\/p>\n<p>\u4e0b\u9762\u5229\u7528connection\u6216connections\u6765\u505a<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_757751\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<div class=\"line number2 index1 alt1\">2<\/div>\n<div class=\"line number3 index2 alt2\">3<\/div>\n<div class=\"line number4 index3 alt1\">4<\/div>\n<div class=\"line number5 index4 alt2\">5<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python keyword\">from<\/code>\u00a0<code class=\"python plain\">django.db\u00a0<\/code><code class=\"python keyword\">import<\/code>\u00a0<code class=\"python plain\">connection, connections<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"python plain\">cursor\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">connection.cursor()\u00a0\u00a0<\/code><code class=\"python comments\"># cursor = connections['default'].cursor()\u00a0\u00a0 # \u83b7\u53d6\u6e38\u6807<\/code><\/div>\n<div class=\"line number4 index3 alt1\"><code class=\"python plain\">cursor.execute(<\/code><code class=\"python comments\">\"\"\"SELECT * FROM auth_user WHERE id = %s\"\"\"<\/code><code class=\"python plain\">, [<\/code><code class=\"python value\">1<\/code><code class=\"python plain\">])\u00a0\u00a0\u00a0<\/code><code class=\"python comments\"># \u4f20sql\u8bed\u53e5<\/code><\/div>\n<div class=\"line number5 index4 alt2\"><code class=\"python plain\">row\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">cursor.fetchone()\u00a0\u00a0\u00a0<\/code><code class=\"python comments\"># \u4e5f\u53ef\u4ee5\u4f7f\u7528fetchmany()<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<h3>\u4f7f\u7528raw()\u65b9\u6cd5<\/h3>\n<p>\u7b2c\u4e8c\u79cd\u662f\u4f7f\u7528QuerySet\u4e2d\u7684raw()\u65b9\u6cd5\u6765\u505a<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_240726\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python plain\">models.UserInfo.objects.raw(<\/code><code class=\"python string\">'SELECT * FROM userinfo WHERE id &gt; %s'<\/code><code class=\"python plain\">, params<\/code><code class=\"python keyword\">=<\/code><code class=\"python plain\">[<\/code><code class=\"python value\">1<\/code><code class=\"python plain\">, ])<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<h3>\u4f7f\u7528extra()\u65b9\u6cd5\u6765\u505a<\/h3>\n<p>\u7b2c\u4e09\u79cd\u540c\u6837\u662f\u4f7f\u7528QuerySet\u7684extra()\u65b9\u6cd5\u6765\u505a<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_114479\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python plain\">models.Entry.objects.extra(select<\/code><code class=\"python keyword\">=<\/code><code class=\"python plain\">{<\/code><code class=\"python string\">'new_id'<\/code><code class=\"python plain\">:\u00a0<\/code><code class=\"python string\">\"SELECT col FROM somtable WHERE othercol &gt; %s\"<\/code><code class=\"python plain\">}, select_params<\/code><code class=\"python keyword\">=<\/code><code class=\"python plain\">(<\/code><code class=\"python value\">1<\/code><code class=\"python plain\">,))<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<p>\u4e0a\u9762\u7684new_id\u662fcol\u7684\u65b0\u540d\u79f0\uff0c\u76f8\u5f53\u4e8e\u00a0<span class=\"cnblogs_code\">SELECT col\u00a0as\u00a0new_id FROM somtable WHERE othercol &gt;%s<\/span><\/p>\n<h2>\u4f18\u5316\u67e5\u8be2<\/h2>\n<p>\u6709\u65f6\u5019\u8fdb\u884c\u67e5\u8be2\uff0c\u5728\u67e5\u8be2\u67d0\u5f20\u8868\u7684\u65f6\u5019\u9700\u8981\u83b7\u53d6\u4e0e\u4e4b\u5173\u8054\u7684\u53e6\u5916\u4e00\u5f20\u8868\u7684\u4fe1\u606f\uff0c\u5047\u8bbe\u6b64\u65f6\u68c0\u7d22\u51fa\u4e865\u6761\u4fe1\u606f\uff0c\u4f46\u8fd8\u8981\u83b7\u53d6\u4e0e\u8fd95\u6761\u4fe1\u606f\u5173\u8054\u7684\u4fe1\u606f\uff0c\u8fd9\u65f6\u5019\u5c31\u53c8\u4f1a\u4ece\u6570\u636e\u5e93\u4e2d\u67e5\u8be2\uff0c\u8fd9\u6837\u5c31\u589e\u52a0\u4e86\u67e5\u8be2\u7684\u6b21\u6570\uff0c\u5982\u4e0b\uff1a<\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_576750\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<div class=\"line number2 index1 alt1\">2<\/div>\n<div class=\"line number3 index2 alt2\">3<\/div>\n<div class=\"line number4 index3 alt1\">4<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python plain\">user\u00a0<\/code><code class=\"python keyword\">=<\/code>\u00a0<code class=\"python plain\">models.UserInfo.objects.<\/code><code class=\"python functions\">filter<\/code><code class=\"python plain\">(id__lt<\/code><code class=\"python keyword\">=<\/code><code class=\"python value\">5<\/code><code class=\"python plain\">)<\/code><\/div>\n<div class=\"line number2 index1 alt1\"><code class=\"python keyword\">for<\/code>\u00a0<code class=\"python plain\">u n user:<\/code><\/div>\n<div class=\"line number3 index2 alt2\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python functions\">print<\/code><code class=\"python plain\">(u.name)<\/code><\/div>\n<div class=\"line number4 index3 alt1\"><code class=\"python spaces\">\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python functions\">print<\/code><code class=\"python plain\">(u.girlfriend.<\/code><code class=\"python functions\">all<\/code><code class=\"python plain\">())\u00a0\u00a0\u00a0\u00a0<\/code><code class=\"python comments\"># grilfriend\u662fUserInfo\u4e0eGrilfriend\u5173\u8054\u7684\u5916\u952e<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<p>\u50cf\u4e0a\u9762\u8fd9\u79cd\u60c5\u51b5\uff0c\u901a\u8fc7user\u53bb\u67e5\u627egrilfriend\uff0c\u6bcf\u6b21\u5faa\u73af\u90fd\u4f1a\u67e5\u627e\u4e00\u6b21\uff0c\u4f1a\u589e\u52a0\u67e5\u8be2\u6b21\u6570\uff0c\u4e5f\u5c31\u662f\u8bf4\u4e0a\u9762\u4e00\u5171\u67e5\u627e\u4e865\u6b21<\/p>\n<p>\u90a3\u4e48\u6709\u6ca1\u6709\u4ec0\u4e48\u65b9\u6cd5\u53ef\u4ee5\u51cf\u5c11\u67e5\u8be2\u6b21\u6570\u5462\uff1f\u5728QuerySet\u4e2d\u8fd8\u771f\u6709\u8fd9\u4e48\u4e24\u4e2a\u65b9\u6cd5\uff0c\u53ef\u4ee5\u4f18\u5316\u67e5\u8be2\uff0c\u5206\u522b\u662f\u00a0<span class=\"cnblogs_code\">select_related<\/span>\u00a0\u8ddf\u00a0<span class=\"cnblogs_code\">prefetch_related<\/span><\/p>\n<h3>select_related(\u4e00\u6b21\u8fde\u8868\u67e5\u8be2\u83b7\u53d6\u6240\u6709\u7684\u6570\u636e)<\/h3>\n<p>\u8fd9\u4e2a\u65b9\u6cd5\u76f8\u5f53\u4e8e\u5728\u67e5\u8be2A\u8868\u7684\u65f6\u5019\u4e5f\u628aB\u8868\u76f8\u5173\u7684\u6570\u636e\u4e00\u8d77\u67e5\u4e86\uff0c\u505a\u4e86\u4e00\u6b21\u8fde\u8868\u64cd\u4f5c\uff0c\u76f8\u5f53\u4e8e\u00a0<span class=\"cnblogs_code\">SELECT\u00a0*\u00a0FROM\u00a0A\u00a0LEFT\u00a0JOIN\u00a0B\u00a0ON\u00a0A.id\u00a0=\u00a0B.nid<\/span>\u00a0\uff0c\u8fd9\u6837\u5c31\u53ea\u9700\u8981\u8fdb\u884c\u4e00\u6b21\u67e5\u8be2\u5c31\u53ef\u4ee5\u83b7\u53d6\u6240\u6709\u6570\u636e<\/p>\n<p><strong>\u4f8b\uff1a<\/strong><\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_300662\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python plain\">models.UserInfo.objects.select_related(<\/code><code class=\"python string\">'girlfriend'<\/code><code class=\"python plain\">)\u00a0\u00a0\u00a0<\/code><code class=\"python comments\"># girlfriend\u662f\u8de8\u8868\u5b57\u6bb5<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<p>\u8fd9\u79cd\u65b9\u5f0f\u867d\u7136\u4f7f\u7528\u8fde\u8868\u64cd\u4f5c\u7b80\u5316\u4e86\u67e5\u8be2\u6b21\u6570\uff0c\u4f46\u662f\u505a\u8fde\u8868\u64cd\u4f5c\u7684\u6027\u80fd\u4f4e\uff0c\u8fd9\u53c8\u662f\u4e00\u4e2a\u95ee\u9898\uff0c\u90a3\u4e48\u600e\u6837\u89e3\u51b3\u5462\uff1f\u8fd9\u6d89\u53ca\u5230\u4e86QuerySet\u7684\u53e6\u5916\u4e00\u4e2a\u65b9\u6cd5prefetch_related<\/p>\n<h3>prefetch_related(\u591a\u6b21\u67e5\u8be2\u63d0\u9ad8\u6548\u7387)<button class=\"cnblogs-toc-button\" title=\"\u663e\u793a\u76ee\u5f55\u5bfc\u822a\"><\/button><\/h3>\n<p>\u8fd9\u4e2a\u65b9\u6cd5\u4e5f\u662f\u5728\u67e5\u8be2A\u8868\u7684\u65f6\u5019\u628aB\u8868\u76f8\u5173\u7684\u6570\u636e\u4e00\u8d77\u67e5\u4e86\uff0c\u4f46\u662f\u4e0e\u4e0a\u9762\u4e0d\u540c\u7684\u662f\u8fd9\u4e2a\u65b9\u6cd5\u5206\u4e86\u591a\u6b21\u53bb\u67e5\u8be2\uff0c\u4e0d\u518d\u4f7f\u7528\u8fde\u8868\u64cd\u4f5c<\/p>\n<p><strong>\u4f8b\uff1a<\/strong><\/p>\n<div class=\"cnblogs_Highlighter sh-gutter\">\n<div>\n<div id=\"highlighter_496353\" class=\"syntaxhighlighter python\">\n<table border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td class=\"gutter\">\n<div class=\"line number1 index0 alt2\">1<\/div>\n<\/td>\n<td class=\"code\">\n<div class=\"container\">\n<div class=\"line number1 index0 alt2\"><code class=\"python plain\">models.UserInfo.objects.prefetch_related(<\/code><code class=\"python string\">'girlfriend'<\/code><code class=\"python plain\">)<\/code><\/div>\n<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n<p>\u8fd9\u79cd\u65b9\u6cd5\u5148\u662f\u8ba1\u7b97\u67e5\u8be2\u5230\u7684\u6570\u636e\u5173\u8054\u7684\u53e6\u4e00\u5f20\u8868\u7684\u8bb0\u5f55\u7684ID\uff0c\u7136\u540e\u518d\u53bb\u53e6\u5916\u4e00\u5f20\u8868\u67e5\u8be2\u51fa\u5c5e\u4e8e\u8fd9\u4e9bid\u7684\u5b57\u6bb5<\/p>\n<p>\u5373\uff1a<\/p>\n<p>select * from UserInfo<\/p>\n<p>\u8ba1\u7b97\u83b7\u53d6\u5230\u6240\u6709\u7528\u6237\u7684\u7528\u6237\u7c7b\u578bID \u00a0[1, 2, 33]\uff0c\u518d\u53bb\u53e6\u5916\u4e00\u5f20\u8868\u67e5\u8be2\u51fa\u8fd9\u4e9bid\u5bf9\u5e94\u7684\u5b57\u6bb5<\/p>\n<p>select * from girlfriend where id in [1, 2, 33]<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Models\u5b57\u6bb5\u8be6\u89e3 AutoField(Field) int\u7c7b\u578b\u81ea\u589e\u5217\uff0c\u5fc5\u987b\u586b\u5165\u53c2\u6570\u00a0primary_key=True BigAutoField(AutoField) bigint\u7c7b\u578b\u81ea\u589e\u5217\uff0c\u5fc5\u987b\u586b\u5165\u53c2\u6570\u00a0primary_key=True [&hellip;]<\/p>\n","protected":false},"author":4,"featured_media":83,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[34,35,15],"topic":[],"class_list":["post-82","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-10","tag-django","tag-models","tag-python"],"_links":{"self":[{"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/posts\/82","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=82"}],"version-history":[{"count":11,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/posts\/82\/revisions"}],"predecessor-version":[{"id":306,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/posts\/82\/revisions\/306"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=\/wp\/v2\/media\/83"}],"wp:attachment":[{"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=82"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=82"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=82"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/idc.birk.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftopic&post=82"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}