{"id":187,"date":"2026-06-17T19:46:28","date_gmt":"2026-06-17T11:46:28","guid":{"rendered":"https:\/\/www.52runoob.com\/?p=187"},"modified":"2026-06-17T19:46:28","modified_gmt":"2026-06-17T11:46:28","slug":"flask-%e6%95%b0%e6%8d%ae%e5%ba%93%e9%9b%86%e6%88%90","status":"publish","type":"post","link":"https:\/\/www.52runoob.com\/index.php\/2026\/06\/17\/flask-%e6%95%b0%e6%8d%ae%e5%ba%93%e9%9b%86%e6%88%90\/","title":{"rendered":"Flask \u6570\u636e\u5e93\u96c6\u6210"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5728\u4e4b\u524d\u7684\u201cFlask \u6570\u636e\u5e93\u64cd\u4f5c\u201d\u4e2d\uff0c\u6211\u4eec\u5b66\u4e60\u4e86\u5982\u4f55\u4f7f\u7528 Flask-SQLAlchemy \u8fdb\u884c\u57fa\u7840\u7684 CRUD\uff08\u589e\u5220\u6539\u67e5\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4eca\u5929\uff0c\u6211\u4eec\u5c06\u89c6\u89d2\u62d4\u9ad8\uff0c\u63a2\u8ba8 <strong>\u201c\u6570\u636e\u5e93\u96c6\u6210 (Database Integration)\u201d<\/strong>\u3002\u8fd9\u4e0d\u4ec5\u4ec5\u662f\u5199\u51e0\u884c\u67e5\u8be2\u4ee3\u7801\uff0c\u800c\u662f\u5173\u4e4e<strong>\u5982\u4f55\u5728\u4f01\u4e1a\u7ea7\u9879\u76ee\u67b6\u6784\u4e2d\u4f18\u96c5\u3001\u9ad8\u6548\u3001\u5b89\u5168\u5730\u5c06\u6570\u636e\u5e93\u4e0e Flask \u5e94\u7528\u7ed3\u5408\u8d77\u6765<\/strong>\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e00\u3001 \u6570\u636e\u5e93\u9009\u578b\u6307\u5357<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u96c6\u6210\u4e4b\u524d\uff0c\u9996\u5148\u8981\u6839\u636e\u4e1a\u52a1\u573a\u666f\u9009\u62e9\u5408\u9002\u7684\u6570\u636e\u5e93\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">\u6570\u636e\u5e93\u7c7b\u578b<\/th><th class=\"has-text-align-left\" data-align=\"left\">\u4ee3\u8868\u4ea7\u54c1<\/th><th class=\"has-text-align-left\" data-align=\"left\">\u9002\u7528\u573a\u666f<\/th><th class=\"has-text-align-left\" data-align=\"left\">Flask \u96c6\u6210\u65b9\u6848<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>\u5173\u7cfb\u578b (RDBMS)<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\"><strong>PostgreSQL<\/strong> (\u9996\u9009), MySQL<\/td><td class=\"has-text-align-left\" data-align=\"left\">\u6838\u5fc3\u4e1a\u52a1\u6570\u636e\u3001\u9700\u8981\u5f3a\u4e00\u81f4\u6027\u3001\u590d\u6742\u5173\u8054\u67e5\u8be2\uff08\u5982\u8ba2\u5355\u3001\u7528\u6237\u3001\u8d22\u52a1\uff09\u3002<\/td><td class=\"has-text-align-left\" data-align=\"left\"><strong>Flask-SQLAlchemy<\/strong><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>\u952e\u503c\/\u7f13\u5b58 (NoSQL)<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\"><strong>Redis<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u9ad8\u9891\u8bfb\u53d6\u3001\u4f1a\u8bdd(Session)\u5b58\u50a8\u3001\u5206\u5e03\u5f0f\u9501\u3001\u6392\u884c\u699c\u3001\u6d88\u606f\u961f\u5217\u3002<\/td><td class=\"has-text-align-left\" data-align=\"left\"><strong>Flask-Redis<\/strong> \u6216\u539f\u751f <code>redis-py<\/code><\/td><\/tr><tr><td class=\"has-text-align-left\" data-align=\"left\"><strong>\u6587\u6863\u578b (NoSQL)<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\"><strong>MongoDB<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\">\u6570\u636e\u7ed3\u6784\u4e0d\u56fa\u5b9a\u3001\u6d77\u91cf\u65e5\u5fd7\u3001\u5185\u5bb9\u7ba1\u7406\u7cfb\u7edf\u3001\u7269\u8054\u7f51\u6570\u636e\u3002<\/td><td class=\"has-text-align-left\" data-align=\"left\"><strong>Flask-PyMongo<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e8c\u3001 \u6838\u5fc3\u96be\u70b9\uff1a\u5728\u201c\u5e94\u7528\u5de5\u5382\u201d\u4e2d\u6b63\u786e\u96c6\u6210<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5927\u578b\u9879\u76ee\u4e2d\uff0c\u6211\u4eec\u4f7f\u7528<strong>\u5e94\u7528\u5de5\u5382\u6a21\u5f0f (<code>create_app<\/code>)<\/strong>\u3002\u65b0\u624b\u6700\u5bb9\u6613\u5728\u8fd9\u91cc\u9047\u5230 <strong>\u201c\u5faa\u73af\u5bfc\u5165 (Circular Import)\u201d<\/strong> \u548c <strong>\u201c\u7f3a\u5c11\u5e94\u7528\u4e0a\u4e0b\u6587 (Working outside of application context)\u201d<\/strong> \u7684\u9519\u8bef\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee5\u4e0b\u662f<strong>\u6807\u51c6\u4e14\u9632\u5751<\/strong>\u7684\u96c6\u6210\u59ff\u52bf\uff1a<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. \u62bd\u79bb\u6269\u5c55\u5b9e\u4f8b (<code>app\/extensions.py<\/code>)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u7edd\u5bf9\u4e0d\u8981<\/strong>\u5728 <code>__init__.py<\/code> \u4e2d\u76f4\u63a5 <code>db = SQLAlchemy(app)<\/code>\uff0c\u8fd9\u4f1a\u5bfc\u81f4\u5faa\u73af\u5bfc\u5165\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># app\/extensions.py\nfrom flask_sqlalchemy import SQLAlchemy\nfrom flask_migrate import Migrate\n\n# 1. \u53ea\u5b9e\u4f8b\u5316\uff0c\u4e0d\u7ed1\u5b9a app\ndb = SQLAlchemy()\nmigrate = Migrate()<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">2. \u5728\u5de5\u5382\u4e2d\u521d\u59cb\u5316 (<code>app\/__init__.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><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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># app\/__init__.py\nfrom flask import Flask\nfrom config import Config\nfrom .extensions import db, migrate\n\ndef create_app(config_class=Config):\n    app = Flask(__name__)\n    app.config.from_object(config_class)\n\n    # 2. \u7ed1\u5b9a\u6269\u5c55\u5230 app\n    db.init_app(app)\n    migrate.init_app(app, db)\n\n    # 3. \u6ce8\u518c\u84dd\u56fe\n    from app.main import main_bp\n    app.register_blueprint(main_bp)\n\n    # 4. \u521b\u5efa\u6570\u636e\u5e93\u8868 (\u4ec5\u9650\u5f00\u53d1\u73af\u5883\uff0c\u751f\u4ea7\u73af\u5883\u8bf7\u7528 flask db upgrade)\n    with app.app_context():\n        # \u5bfc\u5165\u6240\u6709\u6a21\u578b\uff0c\u786e\u4fdd SQLAlchemy \u77e5\u9053\u5b83\u4eec\u7684\u5b58\u5728\n        from app import models \n        db.create_all()\n\n    return app<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">3. \u5b9a\u4e49\u6a21\u578b (<code>app\/models.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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># app\/models.py\nfrom .extensions import db\n\nclass User(db.Model):\n    id = db.Column(db.Integer, primary_key=True)\n    username = db.Column(db.String(64), unique=True, index=True)<\/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\">\u4e09\u3001 \u751f\u4ea7\u73af\u5883\u5fc5\u5907\uff1a\u8fde\u63a5\u6c60\u4e0e\u5f15\u64ce\u914d\u7f6e<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5f00\u53d1\u73af\u5883\uff08SQLite\uff09\u4e2d\uff0c\u4f60\u4e0d\u9700\u8981\u5173\u5fc3\u8fde\u63a5\u6c60\u3002\u4f46\u5728\u751f\u4ea7\u73af\u5883\uff08MySQL\/PostgreSQL\uff09\u4e2d\uff0c\u6570\u636e\u5e93\u8fde\u63a5\u662f\u5b9d\u8d35\u7684\u8d44\u6e90\uff0c\u5fc5\u987b\u914d\u7f6e<strong>\u8fde\u63a5\u6c60 (Connection Pool)<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 <code>config.py<\/code> \u4e2d\u6dfb\u52a0\u4ee5\u4e0b\u914d\u7f6e\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><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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">import os\n\nclass Config:\n    SQLALCHEMY_DATABASE_URI = os.environ.get(&#039;DATABASE_URL&#039;)\n\n    # \u6838\u5fc3\uff1aSQLAlchemy \u5f15\u64ce\u914d\u7f6e (\u9488\u5bf9\u751f\u4ea7\u73af\u5883\u4f18\u5316)\n    SQLALCHEMY_ENGINE_OPTIONS = {\n        # \u8fde\u63a5\u6c60\u5927\u5c0f\uff1a\u4fdd\u6301 10 \u4e2a\u5e38\u9a7b\u8fde\u63a5\n        &#039;pool_size&#039;: 10,\n        # \u6700\u5927\u6ea2\u51fa\u8fde\u63a5\u6570\uff1a\u9ad8\u5cf0\u671f\u5141\u8bb8\u989d\u5916\u521b\u5efa 20 \u4e2a\u8fde\u63a5 (\u603b\u5171\u6700\u591a 30 \u4e2a)\n        &#039;max_overflow&#039;: 20,\n        # \u8fde\u63a5\u56de\u6536\u65f6\u95f4\uff1aMySQL \u9ed8\u8ba4 8 \u5c0f\u65f6\u65ad\u5f00\u7a7a\u95f2\u8fde\u63a5\uff0c\u8bbe\u7f6e 3600 \u79d2\u63d0\u524d\u56de\u6536\uff0c\u9632\u6b62\u4f7f\u7528\u6b7b\u8fde\u63a5\n        &#039;pool_recycle&#039;: 3600,\n        # \u9884\u68c0 ping\uff1a\u6bcf\u6b21\u4ece\u8fde\u63a5\u6c60\u83b7\u53d6\u8fde\u63a5\u524d\uff0c\u5148 ping \u4e00\u4e0b\u6570\u636e\u5e93\uff0c\u786e\u4fdd\u8fde\u63a5\u53ef\u7528 (\u6781\u529b\u63a8\u8350)\n        &#039;pool_pre_ping&#039;: True,\n        # \u83b7\u53d6\u8fde\u63a5\u8d85\u65f6\u65f6\u95f4\n        &#039;pool_timeout&#039;: 30\n    }<\/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\">\u56db\u3001 \u8fdb\u9636\uff1aORM \u4e0e\u539f\u751f SQL \u6df7\u7528<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u867d\u7136 ORM \u5f88\u65b9\u4fbf\uff0c\u4f46\u5728\u6267\u884c<strong>\u590d\u6742\u7edf\u8ba1\u3001\u6279\u91cf\u66f4\u65b0\u3001\u591a\u8868\u590d\u6742 JOIN<\/strong> \u65f6\uff0cORM \u751f\u6210\u7684 SQL \u53ef\u80fd\u6548\u7387\u4f4e\u4e0b\u3002\u6b64\u65f6\u53ef\u4ee5\u76f4\u63a5\u6267\u884c\u539f\u751f SQL\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 SQLAlchemy 2.0+ \u548c Flask-SQLAlchemy 3.0+ \u4e2d\uff0c\u63a8\u8350\u4f7f\u7528 <code>text()<\/code> \u548c <code>db.session.execute()<\/code>\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><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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\">from sqlalchemy import text\nfrom app.extensions import db\n\ndef get_user_statistics():\n    # 1. \u7f16\u5199\u539f\u751f SQL (\u4f7f\u7528 :param \u4f5c\u4e3a\u5360\u4f4d\u7b26\uff0c\u9632\u6b62 SQL \u6ce8\u5165)\n    sql = text(&quot;&quot;&quot;\n        SELECT u.department, COUNT(u.id) as user_count \n        FROM users u\n        WHERE u.status = :status\n        GROUP BY u.department\n    &quot;&quot;&quot;)\n\n    # 2. \u6267\u884c\u5e76\u4f20\u5165\u53c2\u6570\n    result = db.session.execute(sql, {&#039;status&#039;: &#039;active&#039;})\n\n    # 3. \u5904\u7406\u7ed3\u679c\n    stats = []\n    for row in result:\n        stats.append({&#039;department&#039;: row.department, &#039;count&#039;: row.user_count})\n\n    return stats<\/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\">\u4e94\u3001 \u96c6\u6210 NoSQL\uff1a\u4ee5 Redis \u4e3a\u4f8b<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u73b0\u4ee3 Web \u5e94\u7528\u51e0\u4e4e\u79bb\u4e0d\u5f00 Redis\uff08\u7528\u4e8e\u7f13\u5b58\u3001Session\u3001\u9650\u6d41\u7b49\uff09\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. \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 redis<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">2. \u5728\u5de5\u5382\u4e2d\u96c6\u6210<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u6211\u4eec\u4e0d\u9700\u8981\u7279\u5b9a\u7684 Flask \u6269\u5c55\uff0c\u76f4\u63a5\u4f7f\u7528 <code>redis-py<\/code> \u7ed3\u5408 Flask \u7684 <code>g<\/code> \u5bf9\u8c61\u6216\u5e94\u7528\u4e0a\u4e0b\u6587\u5373\u53ef\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><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># app\/extensions.py\nimport redis\nfrom flask import current_app\n\n# \u521b\u5efa\u4e00\u4e2a\u83b7\u53d6 Redis \u5ba2\u6237\u7aef\u7684\u8f85\u52a9\u51fd\u6570\ndef get_redis_client():\n    # \u4f7f\u7528 current_app \u786e\u4fdd\u5728\u5e94\u7528\u4e0a\u4e0b\u6587\u4e2d\n    redis_url = current_app.config.get(&#039;REDIS_URL&#039;, &#039;redis:\/\/localhost:6379\/0&#039;)\n    # \u4e5f\u53ef\u4ee5\u8003\u8651\u5c06 client \u7f13\u5b58\u5728 app.extensions \u4e2d\uff0c\u907f\u514d\u6bcf\u6b21\u8bf7\u6c42\u90fd\u91cd\u65b0\u8fde\u63a5\n    if &#039;redis_client&#039; not in current_app.extensions:\n        current_app.extensions[&#039;redis_client&#039;] = redis.from_url(redis_url, decode_responses=True)\n    return current_app.extensions[&#039;redis_client&#039;]<\/code><\/pre><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">3. \u5728\u89c6\u56fe\u4e2d\u4f7f\u7528<\/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><span>15<\/span><span>16<\/span><span>17<\/span><\/div><pre class=\"chp-pre\" style=\"font-size:14px;\"><code class=\"language-plaintext\"># app\/main\/routes.py\nfrom flask import Blueprint, jsonify\nfrom app.extensions import get_redis_client\n\nmain_bp = Blueprint(&#039;main&#039;, __name__)\n\n@main_bp.route(&#039;\/page-views&#039;)\ndef page_views():\n    r = get_redis_client()\n\n    # \u589e\u52a0\u9875\u9762\u8bbf\u95ee\u91cf\n    views = r.incr(&#039;page:home:views&#039;)\n\n    # \u8bbe\u7f6e\u8fc7\u671f\u65f6\u95f4 (\u53ef\u9009)\n    r.expire(&#039;page:home:views&#039;, 86400) # 1\u5929\n\n    return jsonify({&quot;views&quot;: views})<\/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\">\u516d\u3001 \u6570\u636e\u5e93\u96c6\u6210\u7684\u201c\u907f\u5751\u201d\u6307\u5357<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u4e0a\u4e0b\u6587\u95ee\u9898 (<code>RuntimeError: Working outside of application context<\/code>)<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u539f\u56e0<\/strong>\uff1a\u5728 Flask \u5e94\u7528\u4e0a\u4e0b\u6587\u4e4b\u5916\uff08\u5982\u666e\u901a\u7684 Python \u811a\u672c\u3001Celery \u4efb\u52a1\u3001\u540e\u53f0\u7ebf\u7a0b\uff09\u8bbf\u95ee\u4e86 <code>db<\/code> \u6216 <code>current_app<\/code>\u3002<\/li>\n\n\n\n<li><strong>\u89e3\u51b3<\/strong>\uff1a\u624b\u52a8\u63a8\u5165\u4e0a\u4e0b\u6587\u3002 <code>from app import create_app from app.extensions import db app = create_app() with app.app_context(): # \u5728\u8fd9\u91cc\u6267\u884c\u6570\u636e\u5e93\u64cd\u4f5c db.session.execute(...)<\/code><\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>N+1 \u67e5\u8be2\u95ee\u9898<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u73b0\u8c61<\/strong>\uff1a\u67e5\u8be2 100 \u7bc7\u6587\u7ae0\uff0c\u7136\u540e\u5faa\u73af\u83b7\u53d6\u6bcf\u7bc7\u6587\u7ae0\u7684\u4f5c\u8005\uff0c\u5bfc\u81f4\u6267\u884c\u4e86 101 \u6b21 SQL\u3002<\/li>\n\n\n\n<li><strong>\u89e3\u51b3<\/strong>\uff1a\u4f7f\u7528 <code>joinedload<\/code> \u6216 <code>selectinload<\/code> \u8fdb\u884c\u9884\u52a0\u8f7d\u3002<br><code>python from sqlalchemy.orm import selectinload posts = Post.query.options(selectinload(Post.author)).all()<\/code><\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u4e8b\u52a1\u672a\u63d0\u4ea4\/\u672a\u56de\u6eda<\/strong>\uff1a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Flask-SQLAlchemy \u4f1a\u5728\u8bf7\u6c42\u7ed3\u675f\u65f6\u81ea\u52a8\u63d0\u4ea4\uff08\u5982\u679c\u6ca1\u6709\u5f02\u5e38\uff09\u3002\u4f46\u5982\u679c\u4f60\u5728\u540e\u53f0\u4efb\u52a1\u6216\u81ea\u5b9a\u4e49\u7ebf\u7a0b\u4e2d\u64cd\u4f5c\uff0c<strong>\u5fc5\u987b\u624b\u52a8 <code>db.session.commit()<\/code><\/strong>\uff0c\u5e76\u5728\u5f02\u5e38\u65f6 <code>db.session.rollback()<\/code>\u3002<\/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\udcdd \u603b\u7ed3<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Flask \u6570\u636e\u5e93\u96c6\u6210\u7684\u6838\u5fc3\u5728\u4e8e\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u67b6\u6784\u6e05\u6670<\/strong>\uff1a\u4f7f\u7528 <code>extensions.py<\/code> \u89e3\u8026\uff0c\u4f7f\u7528\u5de5\u5382\u6a21\u5f0f\u521d\u59cb\u5316\u3002<\/li>\n\n\n\n<li><strong>\u751f\u4ea7\u5c31\u7eea<\/strong>\uff1a\u914d\u7f6e\u5408\u7406\u7684\u8fde\u63a5\u6c60\u53c2\u6570 (<code>pool_pre_ping<\/code> \u662f\u6551\u547d\u7a3b\u8349)\u3002<\/li>\n\n\n\n<li><strong>\u7075\u6d3b\u53d8\u901a<\/strong>\uff1aORM \u5904\u7406\u5e38\u89c4\u4e1a\u52a1\uff0c\u539f\u751f SQL \u5904\u7406\u590d\u6742\u7edf\u8ba1\uff0cRedis \u5904\u7406\u9ad8\u9891\u7f13\u5b58\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u81f3\u6b64\uff0c\u4f60\u5df2\u7ecf\u638c\u63e1\u4e86 Flask \u4ece\u57fa\u7840\u8def\u7531\u5230\u751f\u4ea7\u7ea7\u6570\u636e\u5e93\u96c6\u6210\u7684\u5168\u5957\u6280\u80fd\u3002\u5982\u679c\u4f60\u60f3\u7ee7\u7eed\u6df1\u5165\uff0c\u6211\u4eec\u53ef\u4ee5\u63a2\u8ba8\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Flask \u5f02\u6b65\u7f16\u7a0b (Async\/Await)<\/strong>\uff1a\u5982\u4f55\u8ba9 Flask \u652f\u6301\u9ad8\u5e76\u53d1 I\/O\uff1f<\/li>\n\n\n\n<li><strong>Celery \u5f02\u6b65\u4efb\u52a1\u961f\u5217<\/strong>\uff1a\u5982\u4f55\u5904\u7406\u53d1\u90ae\u4ef6\u3001\u751f\u6210\u62a5\u8868\u7b49\u8017\u65f6\u4efb\u52a1\uff1f<\/li>\n\n\n\n<li><strong>\u7f16\u5199\u5355\u5143\u6d4b\u8bd5<\/strong>\uff1a\u5982\u4f55\u6d4b\u8bd5\u4f60\u7684\u6570\u636e\u5e93\u64cd\u4f5c\u548c API\uff1f<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\u5728\u4e4b\u524d\u7684\u201cFlask \u6570\u636e\u5e93\u64cd\u4f5c\u201d\u4e2d\uff0c\u6211\u4eec\u5b66\u4e60\u4e86\u5982\u4f55\u4f7f\u7528 F&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-187","post","type-post","status-publish","format-standard","hentry","category-flask-"],"_links":{"self":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/187","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=187"}],"version-history":[{"count":1,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/187\/revisions"}],"predecessor-version":[{"id":188,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/posts\/187\/revisions\/188"}],"wp:attachment":[{"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/media?parent=187"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/categories?post=187"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.52runoob.com\/index.php\/wp-json\/wp\/v2\/tags?post=187"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}