完成了文档的说明，数据库可选择mysql部署

backend/db.js

@@ -1,9 +1,31 @@
 const { Sequelize } = require('sequelize');
 
-// 创建并导出sequelize实例
-const sequelize = new Sequelize({
-  dialect: 'sqlite',
-  storage: './idc_management.db' // SQLite数据库文件路径
-});
+// 获取数据库配置
+const DB_TYPE = process.env.DB_TYPE || 'sqlite'; // 数据库类型：sqlite 或 mysql
+
+// 根据数据库类型创建连接
+let sequelize;
+
+if (DB_TYPE === 'mysql') {
+  // MySQL 配置
+  sequelize = new Sequelize(
+    process.env.MYSQL_DATABASE || 'idc_management',
+    process.env.MYSQL_USERNAME || 'root',
+    process.env.MYSQL_PASSWORD || '',
+    {
+      host: process.env.MYSQL_HOST || 'localhost',
+      port: parseInt(process.env.MYSQL_PORT) || 3306,
+      dialect: 'mysql',
+      logging: process.env.NODE_ENV === 'development' ? console.log : false
+    }
+  );
+} else {
+  // SQLite 配置（默认）
+  sequelize = new Sequelize({
+    dialect: 'sqlite',
+    storage: process.env.DB_PATH || './idc_management.db',
+    logging: process.env.NODE_ENV === 'development' ? console.log : false
+  });
+}
 
 module.exports = { sequelize };