新增：数据库可见性过滤与连接管理增强

功能：
- 支持配置 MySQL/MongoDB 可见数据库列表
- 连接删除时自动清理关联数据并关闭连接池
- 新增加载数据库列表 API
- 数据库错误提示优化

改进：
- 代码简化：消除重复的表单验证和密码处理逻辑
- ResultPanel 表格高度计算重构
- 删除调试日志和临时文件

后端：
- 新增 VisibleDatabases 字段到连接模型
- DeleteConnection 使用事务确保数据一致性
- LoadAllDatabases 支持 MySQL/MongoDB 数据库列表加载

internal/storage/connection_service.go

@@ -1,6 +1,7 @@
 package storage
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"u-desk/internal/crypto"
@@ -55,13 +56,14 @@ func (s *ConnectionService) SaveConnection(conn *models.DbConnection) error {
 	if conn.ID > 0 {
 		// 更新模式
 		updateData := map[string]interface{}{
-			"name":     conn.Name,
-			"type":     conn.Type,
-			"host":     conn.Host,
-			"port":     conn.Port,
-			"username": conn.Username,
-			"database": conn.Database,
-			"options":  conn.Options,
+			"name":              conn.Name,
+			"type":              conn.Type,
+			"host":              conn.Host,
+			"port":              conn.Port,
+			"username":          conn.Username,
+			"database":          conn.Database,
+			"options":           conn.Options,
+			"visible_databases": conn.VisibleDatabases,
 		}
 
 		// 如果提供了新密码，加密后更新
@@ -111,7 +113,26 @@ func (s *ConnectionService) GetConnection(id uint) (*models.DbConnection, error)
 
 // DeleteConnection 删除连接配置
 func (s *ConnectionService) DeleteConnection(id uint) error {
-	return s.db.Delete(&models.DbConnection{}, id).Error
+	var conn models.DbConnection
+	if err := s.db.First(&conn, id).Error; err != nil {
+		return nil // 连接不存在视为成功
+	}
+
+	// 使用事务删除
+	return s.db.Transaction(func(tx *gorm.DB) error {
+		// 清理关联数据
+		tx.Where("connection_id = ?", id).Delete(&models.SqlResultHistory{})
+		tx.Where("connection_id = ?", id).Delete(&models.SqlTab{})
+
+		// 删除连接
+		if err := tx.Delete(&conn).Error; err != nil {
+			return err
+		}
+
+		// 关闭连接池
+		dbclient.GetPool().CloseConnection(id, conn.Type)
+		return nil
+	})
 }
 
 // TestConnection 测试连接（需要根据类型调用不同的测试方法）
@@ -163,3 +184,127 @@ func testRedisConnection(host string, port int, password string) error {
 func testMongoConnection(host string, port int, username, password, database, authSource, authMechanism string) error {
 	return dbclient.TestMongoConnectionWithOptions(host, port, username, password, database, authSource, authMechanism)
 }
+
+// TestConnectionWithParams 使用参数测试连接（不保存数据）
+func (s *ConnectionService) TestConnectionWithParams(dbType, host string, port int, username, password, database, options string, id uint) error {
+	// 如果是编辑模式且有ID，获取已保存的密码
+	if id > 0 && password == "" {
+		conn, err := s.GetConnection(id)
+		if err != nil {
+			return fmt.Errorf("获取连接信息失败: %v", err)
+		}
+		decryptPassword, err := crypto.DecryptPassword(conn.Password)
+		if err != nil {
+			return fmt.Errorf("密码解密失败: %v", err)
+		}
+		password = decryptPassword
+	}
+
+	// 根据类型测试连接
+	switch dbType {
+	case "mysql":
+		return testMySQLConnection(host, port, username, password, database)
+	case "redis":
+		return testRedisConnection(host, port, password)
+	case "mongo":
+		// 解析 Options 获取 MongoDB 连接参数
+		authSource := ""
+		authMechanism := ""
+		if options != "" {
+			var opts map[string]interface{}
+			if err := json.Unmarshal([]byte(options), &opts); err == nil {
+				if as, ok := opts["authSource"].(string); ok && as != "" {
+					authSource = as
+				}
+				if am, ok := opts["authMechanism"].(string); ok && am != "" {
+					authMechanism = am
+				}
+			}
+		}
+		return testMongoConnection(host, port, username, password, database, authSource, authMechanism)
+	default:
+		return fmt.Errorf("不支持的数据库类型: %s", dbType)
+	}
+}
+
+// LoadAllDatabases 加载全部数据库列表
+func (s *ConnectionService) LoadAllDatabases(dbType, host string, port int, username, password, database, options string, id uint) ([]string, error) {
+	// 如果是编辑模式且有ID，获取已保存的密码
+	if id > 0 && password == "" {
+		conn, err := s.GetConnection(id)
+		if err != nil {
+			return nil, fmt.Errorf("获取连接信息失败: %v", err)
+		}
+		decryptPassword, err := crypto.DecryptPassword(conn.Password)
+		if err != nil {
+			return nil, fmt.Errorf("密码解密失败: %v", err)
+		}
+		password = decryptPassword
+	}
+
+	// 根据类型加载数据库列表
+	switch dbType {
+	case "mysql":
+		return loadMySQLDatabases(host, port, username, password, database)
+	case "mongo":
+		return loadMongoDatabases(host, port, username, password, database, options)
+	case "redis":
+		// Redis 没有数据库概念，返回空列表
+		return []string{}, nil
+	default:
+		return nil, fmt.Errorf("不支持的数据库类型: %s", dbType)
+	}
+}
+
+// loadMySQLDatabases 加载 MySQL 数据库列表
+func loadMySQLDatabases(host string, port int, username, password, defaultDatabase string) ([]string, error) {
+	config := &dbclient.MySQLConfig{
+		Host:     host,
+		Port:     port,
+		Username: username,
+		Password: password,
+		Database: defaultDatabase,
+	}
+	client, err := dbclient.NewMySQLClient(config)
+	if err != nil {
+		return nil, err
+	}
+	defer client.Close()
+
+	return client.ListDatabases(context.Background())
+}
+
+// loadMongoDatabases 加载 MongoDB 数据库列表
+func loadMongoDatabases(host string, port int, username, password, defaultDatabase, options string) ([]string, error) {
+	// 解析 Options 获取 MongoDB 连接参数
+	authSource := ""
+	authMechanism := ""
+	if options != "" {
+		var opts map[string]interface{}
+		if err := json.Unmarshal([]byte(options), &opts); err == nil {
+			if as, ok := opts["authSource"].(string); ok && as != "" {
+				authSource = as
+			}
+			if am, ok := opts["authMechanism"].(string); ok && am != "" {
+				authMechanism = am
+			}
+		}
+	}
+
+	mongoConfig := &dbclient.MongoConfig{
+		Host:          host,
+		Port:          port,
+		Username:      username,
+		Password:      password,
+		Database:      defaultDatabase,
+		AuthSource:    authSource,
+		AuthMechanism: authMechanism,
+	}
+	client, err := dbclient.NewMongoClient(mongoConfig)
+	if err != nil {
+		return nil, err
+	}
+	defer client.Close()
+
+	return client.ListDatabases(context.Background())
+}