Enhance database configuration to support multiple data sources

- Updated .env.example to include optional configuration for additional database instances.
- Refactored DatabaseConfig in config.go to accommodate a default database and additional instances.
- Implemented loadAdditionalDBConfigs function to dynamically load configurations for extra databases.
- Modified InitDB function in database.go to establish connections for both default and additional databases.
- Updated README.md to document the new configuration options for connecting to multiple databases.

.env.example

@@ -8,6 +8,13 @@ DB_PORT=3306
 DB_USER=root
 DB_PASSWORD=your_password
 DB_NAME=wx_service
+# 多数据源（可选）
+# DB_INSTANCES=lawyer,reporting
+# DB_LAWYER_HOST=127.0.0.1
+# DB_LAWYER_PORT=3306
+# DB_LAWYER_USER=another_user
+# DB_LAWYER_PASSWORD=another_password
+# DB_LAWYER_NAME=lawyer
 
 # JWT配置
 JWT_SECRET=your-secret-key-change-in-production

config/config.go

@@ -4,6 +4,7 @@ import (
 	"log"
 	"os"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/joho/godotenv"
@@ -27,6 +28,11 @@ type ServerConfig struct {
 }
 
 type DatabaseConfig struct {
+	Default    DatabaseInstanceConfig
+	Additional map[string]DatabaseInstanceConfig
+}
+
+type DatabaseInstanceConfig struct {
 	Host     string
 	Port     string
 	User     string
@@ -94,17 +100,22 @@ func LoadConfig() {
 		log.Println("未找到 .env 文件，使用环境变量")
 	}
 
+	defaultDB := DatabaseInstanceConfig{
+		Host:     getEnv("DB_HOST", "localhost"),
+		Port:     getEnv("DB_PORT", "3306"),
+		User:     getEnv("DB_USER", "root"),
+		Password: getEnv("DB_PASSWORD", ""),
+		DBName:   getEnv("DB_NAME", "wx_service"),
+	}
+
 	AppConfig = &Config{
 		Server: ServerConfig{
 			Port: getEnv("SERVER_PORT", "8080"),
 			Mode: getEnv("GIN_MODE", "debug"),
 		},
 		Database: DatabaseConfig{
-			Host:     getEnv("DB_HOST", "localhost"),
-			Port:     getEnv("DB_PORT", "3306"),
-			User:     getEnv("DB_USER", "root"),
-			Password: getEnv("DB_PASSWORD", ""),
-			DBName:   getEnv("DB_NAME", "wx_service"),
+			Default:    defaultDB,
+			Additional: loadAdditionalDBConfigs(defaultDB),
 		},
 		JWT: JWTConfig{
 			Secret: getEnv("JWT_SECRET", "your-secret-key"),
@@ -148,6 +159,30 @@ func LoadConfig() {
 	}
 }
 
+func loadAdditionalDBConfigs(defaultCfg DatabaseInstanceConfig) map[string]DatabaseInstanceConfig {
+	instances := strings.Split(getEnv("DB_INSTANCES", ""), ",")
+	result := make(map[string]DatabaseInstanceConfig)
+	for _, rawName := range instances {
+		name := strings.TrimSpace(rawName)
+		if name == "" {
+			continue
+		}
+		upperName := strings.ToUpper(name)
+		prefix := "DB_" + upperName + "_"
+		result[strings.ToLower(name)] = DatabaseInstanceConfig{
+			Host:     getEnv(prefix+"HOST", defaultCfg.Host),
+			Port:     getEnv(prefix+"PORT", defaultCfg.Port),
+			User:     getEnv(prefix+"USER", defaultCfg.User),
+			Password: getEnv(prefix+"PASSWORD", defaultCfg.Password),
+			DBName:   getEnv(prefix+"NAME", defaultCfg.DBName),
+		}
+	}
+	if len(result) == 0 {
+		return nil
+	}
+	return result
+}
+
 func getEnv(key, defaultValue string) string {
 	if value := os.Getenv(key); value != "" {
 		return value

docs/README.md

@@ -27,6 +27,7 @@
 2. 按实际环境填写以下变量：
    - `SERVER_PORT`：HTTP 服务端口，例如 `8080`。
    - `DB_HOST/DB_PORT/DB_USER/DB_PASSWORD/DB_NAME`：MySQL 连接信息。
+   - 若需连接额外数据库，可设置 `DB_INSTANCES=lawyer,reporting` 并依次提供 `DB_<NAME>_HOST/PORT/USER/PASSWORD/NAME`；未指定的字段会回落到默认数据库的同名配置。
 3. 如果需要，替换 `GIN_MODE`、`JWT_SECRET` 等其他变量。
 4. 通过 `docs/sql/users.sql` 初始化 `mini_programs` 与 `users` 表，并插入每个小程序的 `name/app_id/app_secret`。
 

internal/database/database.go

@@ -11,11 +11,38 @@ import (
 	"gorm.io/gorm/logger"
 )
 
-var DB *gorm.DB
+var (
+	DB            *gorm.DB
+	additionalDBs map[string]*gorm.DB
+)
 
 func InitDB() error {
 	cfg := config.AppConfig.Database
 
+	defaultDB, err := openConnection(cfg.Default)
+	if err != nil {
+		return fmt.Errorf("连接数据库失败: %v", err)
+	}
+	DB = defaultDB
+	log.Println("默认数据库连接成功")
+
+	if len(cfg.Additional) > 0 {
+		additionalDBs = make(map[string]*gorm.DB)
+		for name, instanceCfg := range cfg.Additional {
+			conn, err := openConnection(instanceCfg)
+			if err != nil {
+				return fmt.Errorf("连接数据库[%s]失败: %v", name, err)
+			}
+			additionalDBs[strings.ToLower(name)] = conn
+			log.Printf("数据库连接成功: %s\n", name)
+		}
+	} else {
+		additionalDBs = nil
+	}
+	return nil
+}
+
+func openConnection(cfg config.DatabaseInstanceConfig) (*gorm.DB, error) {
 	dsn := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=utf8mb4&parseTime=True&loc=Local",
 		cfg.User,
 		cfg.Password,
@@ -24,17 +51,24 @@ func InitDB() error {
 		cfg.DBName,
 	)
 
-	var err error
-	DB, err = gorm.Open(mysql.Open(dsn), &gorm.Config{
+	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{
 		Logger: logger.Default.LogMode(logger.Info),
 	})
-
 	if err != nil {
-		return fmt.Errorf("连接数据库失败: %v", err)
+		return nil, err
+	}
+	return db, nil
 }
 
-	log.Println("数据库连接成功")
-	return nil
+func GetAdditionalDB(name string) (*gorm.DB, bool) {
+	if name == "" || strings.EqualFold(name, "default") {
+		return DB, DB != nil
+	}
+	if additionalDBs == nil {
+		return nil, false
+	}
+	db, ok := additionalDBs[strings.ToLower(name)]
+	return db, ok
 }
 
 func AutoMigrate(models ...interface{}) error {