{"id":177,"date":"2026-06-17T19:37:35","date_gmt":"2026-06-17T11:37:35","guid":{"rendered":"https:\/\/www.52runoob.com\/?p=177"},"modified":"2026-06-17T19:37:35","modified_gmt":"2026-06-17T11:37:35","slug":"flask-%e6%95%b0%e6%8d%ae%e5%ba%93%e6%93%8d%e4%bd%9c","status":"publish","type":"post","link":"https:\/\/www.52runoob.com\/index.php\/2026\/06\/17\/flask-%e6%95%b0%e6%8d%ae%e5%ba%93%e6%93%8d%e4%bd%9c\/","title":{"rendered":"Flask \u6570\u636e\u5e93\u64cd\u4f5c"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5728 Flask \u4e2d\uff0c\u6700\u4e3b\u6d41\u7684\u6570\u636e\u5e93\u64cd\u4f5c\u65b9\u5f0f\u662f\u4f7f\u7528 <strong>ORM\uff08\u5bf9\u8c61\u5173\u7cfb\u6620\u5c04\uff09<\/strong>\u3002\u5b83\u5c06\u6570\u636e\u5e93\u4e2d\u7684\u201c\u8868\u201d\u6620\u5c04\u4e3a Python \u7684\u201c\u7c7b\u201d\uff0c\u5c06\u201c\u884c\u201d\u6620\u5c04\u4e3a\u201c\u5bf9\u8c61\u201d\u3002\u8fd9\u6837\u4f60\u5c31\u53ef\u4ee5\u7528 Python \u4ee3\u7801\u800c\u4e0d\u662f SQL \u8bed\u53e5\u6765\u64cd\u4f5c\u6570\u636e\u5e93\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e1a\u754c\u6807\u51c6\u662f <strong>Flask-SQLAlchemy<\/strong>\uff0c\u5b83\u662f SQLAlchemy \u7684 Flask \u6269\u5c55\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udee0\ufe0f 1. \u5b89\u88c5\u4e0e\u914d\u7f6e<\/h3>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">pip install flask-sqlalchemy<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">\u57fa\u7840\u914d\u7f6e (<code>app\/__init__.py<\/code> \u6216 <code>config.py<\/code>)<\/h4>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><span>13<\/span><span>14<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">from flask import Flask\nfrom flask_sqlalchemy import SQLAlchemy\n\napp = Flask(__name__)\n\n# \u914d\u7f6e\u6570\u636e\u5e93 URI (\u8fd9\u91cc\u4ee5 SQLite \u4e3a\u4f8b\uff0c\u751f\u4ea7\u73af\u5883\u5e38\u7528 MySQL \u6216 PostgreSQL)\n# SQLite: sqlite:\/\/\/database.db\n# MySQL: mysql+pymysql:\/\/user:password@localhost\/db_name\n# PostgreSQL: postgresql:\/\/user:password@localhost\/db_name\napp.config[&#039;SQLALCHEMY_DATABASE_URI&#039;] = &#039;sqlite:\/\/\/site.db&#039;\napp.config[&#039;SQLALCHEMY_TRACK_MODIFICATIONS&#039;] = False  # \u5173\u95ed\u4e0d\u5fc5\u8981\u7684\u4fe1\u53f7\u8ffd\u8e2a\uff0c\u8282\u7701\u5185\u5b58\n\n# \u521d\u59cb\u5316\u6570\u636e\u5e93\u5b9e\u4f8b\ndb = SQLAlchemy(app)<\/code><\/pre><\/div><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83c\udfd7\ufe0f 2. \u5b9a\u4e49\u6a21\u578b (Model)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u6a21\u578b\u662f\u4e00\u4e2a Python \u7c7b\uff0c\u7ee7\u627f\u81ea <code>db.Model<\/code>\u3002\u7c7b\u7684\u5c5e\u6027\u5bf9\u5e94\u6570\u636e\u5e93\u7684\u5217\u3002<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><span>13<\/span><span>14<\/span><span>15<\/span><span>16<\/span><span>17<\/span><span>18<\/span><span>19<\/span><span>20<\/span><span>21<\/span><span>22<\/span><span>23<\/span><span>24<\/span><span>25<\/span><span>26<\/span><span>27<\/span><span>28<\/span><span>29<\/span><span>30<\/span><span>31<\/span><span>32<\/span><span>33<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># models.py\nfrom app import db\nfrom datetime import datetime\n\nclass User(db.Model):\n    __tablename__ = &#039;users&#039;  # \u53ef\u9009\uff1a\u6307\u5b9a\u8868\u540d\uff0c\u9ed8\u8ba4\u662f\u7c7b\u540d\u5c0f\u5199\n\n    id = db.Column(db.Integer, primary_key=True)\n    username = db.Column(db.String(80), unique=True, nullable=False)\n    email = db.Column(db.String(120), unique=True, nullable=False)\n    password_hash = db.Column(db.String(256))\n    created_at = db.Column(db.DateTime, default=datetime.utcnow)\n\n    # \u5efa\u7acb\u4e00\u5bf9\u591a\u5173\u7cfb\uff1a\u4e00\u4e2a\u7528\u6237\u53ef\u4ee5\u6709\u591a\u7bc7\u6587\u7ae0\n    # backref=&#039;author&#039; \u5141\u8bb8\u901a\u8fc7 Post.author \u8bbf\u95ee\u7528\u6237\u5bf9\u8c61\n    posts = db.relationship(&#039;Post&#039;, backref=&#039;author&#039;, lazy=True)\n\n    def __repr__(self):\n        return f&#039;&lt;User {self.username}&gt;&#039;\n\nclass Post(db.Model):\n    __tablename__ = &#039;posts&#039;\n\n    id = db.Column(db.Integer, primary_key=True)\n    title = db.Column(db.String(200), nullable=False)\n    content = db.Column(db.Text, nullable=False)\n    date_posted = db.Column(db.DateTime, default=datetime.utcnow)\n\n    # \u5916\u952e\uff1a\u5173\u8054\u5230 users \u8868\u7684 id\n    user_id = db.Column(db.Integer, db.ForeignKey(&#039;users.id&#039;), nullable=False)\n\n    def __repr__(self):\n        return f&#039;&lt;Post {self.title}&gt;&#039;<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5e38\u7528\u5b57\u6bb5\u7c7b\u578b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>db.Integer<\/code>: \u6574\u6570<\/li>\n\n\n\n<li><code>db.String(n)<\/code>: \u53d8\u957f\u5b57\u7b26\u4e32<\/li>\n\n\n\n<li><code>db.Text<\/code>: \u957f\u6587\u672c<\/li>\n\n\n\n<li><code>db.Float<\/code>: \u6d6e\u70b9\u6570<\/li>\n\n\n\n<li><code>db.Boolean<\/code>: \u5e03\u5c14\u503c<\/li>\n\n\n\n<li><code>db.DateTime<\/code>: \u65e5\u671f\u65f6\u95f4<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5e38\u7528\u7ea6\u675f\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>primary_key=True<\/code>: \u4e3b\u952e<\/li>\n\n\n\n<li><code>unique=True<\/code>: \u552f\u4e00\u7d22\u5f15<\/li>\n\n\n\n<li><code>nullable=False<\/code>: \u4e0d\u5141\u8bb8\u4e3a\u7a7a<\/li>\n\n\n\n<li><code>default=value<\/code>: \u9ed8\u8ba4\u503c<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd04 3. \u6570\u636e\u5e93\u8fc1\u79fb (Flask-Migrate)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5343\u4e07\u4e0d\u8981\u624b\u52a8\u4fee\u6539\u6570\u636e\u5e93\u7ed3\u6784\uff01<\/strong> \u5f53\u4f60\u7684 Model \u53d1\u751f\u53d8\u5316\u65f6\uff08\u5982\u6dfb\u52a0\u65b0\u5b57\u6bb5\uff09\uff0c\u9700\u8981\u4f7f\u7528\u8fc1\u79fb\u5de5\u5177\u81ea\u52a8\u66f4\u65b0\u6570\u636e\u5e93\u8868\u7ed3\u6784\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u5b89\u88c5<\/h4>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">pip install flask-migrate<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">\u521d\u59cb\u5316<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 <code>app\/__init__.py<\/code> \u4e2d\u96c6\u6210\uff1a<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">from flask_migrate import Migrate\n\nmigrate = Migrate(app, db)<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">\u5e38\u7528\u547d\u4ee4<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u9879\u76ee\u6839\u76ee\u5f55\u4e0b\u6267\u884c\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u521d\u59cb\u5316\u8fc1\u79fb\u6587\u4ef6\u5939<\/strong>\uff08\u53ea\u9700\u6267\u884c\u4e00\u6b21\uff09\uff1a<\/li>\n<\/ol>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">   flask db init<\/code><\/pre><\/div><\/div>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u751f\u6210\u8fc1\u79fb\u811a\u672c<\/strong>\uff08\u6bcf\u6b21\u4fee\u6539 Model \u540e\u6267\u884c\uff09\uff1a<\/li>\n<\/ol>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">   flask db migrate -m &quot;\u6dfb\u52a0\u7528\u6237\u90ae\u7bb1\u5b57\u6bb5&quot;<\/code><\/pre><\/div><\/div>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u5e94\u7528\u8fc1\u79fb\u5230\u6570\u636e\u5e93<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">   flask db upgrade<\/code><\/pre><\/div><\/div>\n\n\n\n<ol start=\"4\" class=\"wp-block-list\">\n<li><strong>\u56de\u6eda\u8fc1\u79fb<\/strong>\uff08\u5982\u679c\u51fa\u9519\u4e86\uff09\uff1a<\/li>\n<\/ol>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">   flask db downgrade<\/code><\/pre><\/div><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udcbb 4. CRUD \u64cd\u4f5c\u5b9e\u6218<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">A. \u521b\u5efa (Create)<\/h4>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">from app import db\nfrom app.models import User, Post\n\n# \u521b\u5efa\u65b0\u7528\u6237\nnew_user = User(username=&#039;john&#039;, email=&#039;john@example.com&#039;)\ndb.session.add(new_user)\ndb.session.commit()  # \u5fc5\u987b\u63d0\u4ea4\u624d\u80fd\u5199\u5165\u6570\u636e\u5e93\n\n# \u521b\u5efa\u6587\u7ae0\u5e76\u5173\u8054\u7528\u6237\nnew_post = Post(title=&#039;Hello Flask&#039;, content=&#039;This is my first post.&#039;, author=new_user)\ndb.session.add(new_post)\ndb.session.commit()<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">B. \u67e5\u8be2 (Read)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">SQLAlchemy \u63d0\u4f9b\u4e86\u5f3a\u5927\u7684\u67e5\u8be2\u63a5\u53e3\u3002<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><span>13<\/span><span>14<\/span><span>15<\/span><span>16<\/span><span>17<\/span><span>18<\/span><span>19<\/span><span>20<\/span><span>21<\/span><span>22<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># 1. \u67e5\u8be2\u6240\u6709\u7528\u6237\nall_users = User.query.all()\n\n# 2. \u6839\u636e\u4e3b\u952e\u67e5\u8be2\nuser = User.query.get(1)\n\n# 3. \u8fc7\u6ee4\u67e5\u8be2 (Filter)\n# SELECT * FROM users WHERE username = &#039;john&#039;\nuser_john = User.query.filter_by(username=&#039;john&#039;).first()\n\n# \u590d\u6742\u8fc7\u6ee4\n# SELECT * FROM users WHERE username LIKE &#039;%j%&#039;\nusers_like_j = User.query.filter(User.username.like(&#039;%j%&#039;)).all()\n\n# 4. \u6392\u5e8f\nposts = Post.query.order_by(Post.date_posted.desc()).all()\n\n# 5. \u5206\u9875 (Web \u5f00\u53d1\u6700\u5e38\u7528)\n# \u83b7\u53d6\u7b2c 1 \u9875\uff0c\u6bcf\u9875 10 \u6761\npage_obj = Post.query.paginate(page=1, per_page=10)\nposts_on_page = page_obj.items\ntotal_pages = page_obj.pages<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">C. \u66f4\u65b0 (Update)<\/h4>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">user = User.query.get(1)\nuser.email = &#039;new_email@example.com&#039;\ndb.session.commit()<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">D. \u5220\u9664 (Delete)<\/h4>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">user = User.query.get(1)\ndb.session.delete(user)\ndb.session.commit()<\/code><\/pre><\/div><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd17 5. \u5173\u7cfb\u67e5\u8be2 (Relationships)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5229\u7528\u6211\u4eec\u5728 Model \u4e2d\u5b9a\u4e49\u7684 <code>relationship<\/code>\uff0c\u53ef\u4ee5\u975e\u5e38\u65b9\u4fbf\u5730\u8fdb\u884c\u5173\u8054\u67e5\u8be2\u3002<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><span>13<\/span><span>14<\/span><span>15<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># 1. \u83b7\u53d6\u67d0\u4e2a\u7528\u6237\u7684\u6240\u6709\u6587\u7ae0\nuser = User.query.get(1)\nfor post in user.posts:\n    print(post.title)\n\n# 2. \u83b7\u53d6\u67d0\u7bc7\u6587\u7ae0\u7684\u4f5c\u8005\npost = Post.query.get(1)\nprint(post.author.username)\n\n# 3. \u8054\u5408\u67e5\u8be2 (Join)\n# \u67e5\u8be2\u6240\u6709\u6807\u9898\u5305\u542b &quot;Flask&quot; \u7684\u6587\u7ae0\u53ca\u5176\u4f5c\u8005\u540d\nresults = db.session.query(Post.title, User.username)\\\n    .join(User, Post.user_id == User.id)\\\n    .filter(Post.title.like(&#039;%Flask%&#039;))\\\n    .all()<\/code><\/pre><\/div><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u26a0\ufe0f \u5e38\u89c1\u9677\u9631\u4e0e\u6700\u4f73\u5b9e\u8df5<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u8bb0\u5f97 commit<\/strong>\uff1a\u6240\u6709\u7684\u589e\u5220\u6539\u64cd\u4f5c\u6700\u540e\u90fd\u5fc5\u987b\u8c03\u7528 <code>db.session.commit()<\/code>\uff0c\u5426\u5219\u6570\u636e\u4e0d\u4f1a\u6301\u4e45\u5316\u3002<\/li>\n\n\n\n<li><strong>\u4e8b\u52a1\u56de\u6eda<\/strong>\uff1a\u5982\u679c\u53d1\u751f\u5f02\u5e38\uff0c\u5efa\u8bae\u56de\u6eda\u4e8b\u52a1\u4ee5\u4fdd\u6301\u6570\u636e\u4e00\u81f4\u6027\u3002<\/li>\n<\/ol>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">   try:\n       db.session.add(some_object)\n       db.session.commit()\n   except Exception as e:\n       db.session.rollback()\n       raise e<\/code><\/pre><\/div><\/div>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>N+1 \u67e5\u8be2\u95ee\u9898<\/strong>\uff1a\u5728\u5faa\u73af\u4e2d\u8bbf\u95ee\u5173\u8054\u5bf9\u8c61\u4f1a\u5bfc\u81f4\u5927\u91cf\u6570\u636e\u5e93\u67e5\u8be2\u3002<br><em>\u9519\u8bef\u793a\u4f8b<\/em>\uff1a<\/li>\n<\/ol>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">   posts = Post.query.all()\n   for post in posts:\n       print(post.author.username) # \u6bcf\u6b21\u5faa\u73af\u90fd\u67e5\u4e00\u6b21\u6570\u636e\u5e93\uff01<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><em>\u4f18\u5316<\/em>\uff1a\u4f7f\u7528 <code>joinedload<\/code> \u9884\u52a0\u8f7d\u3002<\/p>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">   from sqlalchemy.orm import joinedload\n   posts = Post.query.options(joinedload(Post.author)).all()<\/code><\/pre><\/div><\/div>\n\n\n\n<ol start=\"4\" class=\"wp-block-list\">\n<li><strong>\u4e0d\u8981\u5728\u751f\u4ea7\u73af\u5883\u4f7f\u7528 SQLite<\/strong>\uff1aSQLite \u662f\u6587\u4ef6\u578b\u6570\u636e\u5e93\uff0c\u5e76\u53d1\u6027\u80fd\u5dee\u3002\u751f\u4ea7\u73af\u5883\u8bf7\u4f7f\u7528 <strong>PostgreSQL<\/strong> \u6216 <strong>MySQL<\/strong>\u3002<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udcdd \u603b\u7ed3\u6d41\u7a0b\u56fe<\/h3>\n\n\n\n<div class=\"chp-code-block chp-theme-github-dark chp-wrap-on\" data-chp-language=\"plaintext\" data-chp-line-start=\"1\" data-chp-highlight=\"\"><div class=\"chp-toolbar\"><div class=\"chp-toolbar-left\"><span class=\"chp-dots\"><span><\/span><span><\/span><span><\/span><\/span><span class=\"chp-language-label\">\u7eaf\u6587\u672c<\/span><\/div><div class=\"chp-toolbar-right\"><button type=\"button\" class=\"chp-copy-btn\" aria-label=\"\u590d\u5236\u4ee3\u7801\"><svg class=\"chp-icon-copy\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\"><path fill=\"currentColor\" d=\"M16 1H4c-1.1 0-2 .9-2 2v14h2V3h12V1zm3 4H8c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h11c1.1 0 2-.9 2-2V7c0-1.1-.9-2-2-2zm0 16H8V7h11v14z\"\/><\/svg><svg class=\"chp-icon-check\" viewBox=\"0 0 24 24\" width=\"14\" height=\"14\" aria-hidden=\"true\" style=\"display:none;\"><path fill=\"currentColor\" d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><span class=\"chp-copy-text\">\u590d\u5236<\/span><\/button><\/div><\/div><div class=\"chp-code-wrapper\"><div class=\"chp-line-numbers\" aria-hidden=\"true\"><span>1<\/span><span>2<\/span><span>3<\/span><span>4<\/span><span>5<\/span><span>6<\/span><span>7<\/span><span>8<\/span><span>9<\/span><span>10<\/span><span>11<\/span><span>12<\/span><span>13<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">\u5b9a\u4e49 Model (Python \u7c7b) \n      \u2193\nflask db migrate (\u751f\u6210\u8fc1\u79fb\u811a\u672c)\n      \u2193\nflask db upgrade (\u66f4\u65b0\u6570\u636e\u5e93\u8868\u7ed3\u6784)\n      \u2193\n\u89c6\u56fe\u51fd\u6570\u4e2d:\n   db.session.add(obj) -&gt; \u65b0\u589e\n   Model.query.filter(...) -&gt; \u67e5\u8be2\n   obj.field = value -&gt; \u4fee\u6539\n   db.session.delete(obj) -&gt; \u5220\u9664\n      \u2193\ndb.session.commit() (\u63d0\u4ea4\u4e8b\u52a1)<\/code><\/pre><\/div><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u638c\u63e1\u4e86\u6570\u636e\u5e93\u64cd\u4f5c\uff0c\u4f60\u7684 Flask \u5e94\u7528\u5c31\u62e5\u6709\u4e86\u201c\u8bb0\u5fc6\u201d\u3002\u63a5\u4e0b\u6765\uff0c\u4f60\u60f3\u5b66\u4e60\u5982\u4f55\u7ed3\u5408 <strong>Flask-Login<\/strong> \u5b9e\u73b0\u5b8c\u6574\u7684<strong>\u7528\u6237\u8ba4\u8bc1\u7cfb\u7edf<\/strong>\uff0c\u8fd8\u662f\u5b66\u4e60\u5982\u4f55\u6784\u5efa <strong>RESTful API<\/strong>\uff1f<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 Flask \u4e2d\uff0c\u6700\u4e3b\u6d41\u7684\u6570\u636e\u5e93\u64cd\u4f5c\u65b9\u5f0f\u662f\u4f7f\u7528 ORM\uff08\u5bf9&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-177","post","type-post","status-publish","format-standard","hentry","category-flask-"],"_links":{"self":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/177","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/comments?post=177"}],"version-history":[{"count":1,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/177\/revisions"}],"predecessor-version":[{"id":178,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/177\/revisions\/178"}],"wp:attachment":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/media?parent=177"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/categories?post=177"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/tags?post=177"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}