面向文档的数据结构概述

在工业自动化领域，数据模型的灵活性和可扩展性至关重要。LiteDB 作为一个轻量级的文档数据库，为复杂的工业数据建模提供了理想的解决方案。

文档模型的核心优势

1. 灵活架构：无需预定义严格的架构
2. 嵌套对象支持：可以轻松存储复杂的层次结构
3. 动态字段：可以随时添加或移除字段
4. 高性能：针对文档型数据的快速读写

工业自动化数据建模实例

设备状态监控模型

C#
// 设备基础信息类
public class DeviceInfo
{
    // 唯一标识
    public int Id { get; set; }
    
    // 设备基本属性
    public string DeviceName { get; set; }
    public string DeviceModel { get; set; }
    public string Manufacturer { get; set; }

    // 设备状态信息
    public DeviceStatus CurrentStatus { get; set; }

    // 性能指标
    public PerformanceMetrics Performance { get; set; }

    // 历史告警记录
    public List<AlarmRecord> AlarmHistory { get; set; }
}

// 设备状态枚举
public enum DeviceStatus
{
    Running,
    Stopped,
    Maintenance,
    Error
}

// 性能指标
public class PerformanceMetrics
{
    public double OperationEfficiency { get; set; }
    public double EnergyConsumption { get; set; }
    public int TotalRunningHours { get; set; }
}

// 告警记录
public class AlarmRecord
{
    public DateTime Timestamp { get; set; }
    public string AlarmType { get; set; }
    public string Description { get; set; }
    public AlarmSeverity Severity { get; set; }
}

public enum AlarmSeverity
{
    Low,
    Medium,
    High,
    Critical
}

LiteDB 存储与查询示例

C#
public class DeviceRepository
{
    private LiteDatabase _database;
    private ILiteCollection<DeviceInfo> _deviceCollection;

    public DeviceRepository(string databasePath)
    {
        // 初始化数据库连接
        _database = new LiteDatabase(databasePath);
        _deviceCollection = _database.GetCollection<DeviceInfo>("devices");
    }

    // 插入设备信息
    public void InsertDevice(DeviceInfo device)
    {
        _deviceCollection.Insert(device);
    }

    // 根据状态查询设备
    public List<DeviceInfo> GetDevicesByStatus(DeviceStatus status)
    {
        return _deviceCollection
            .Find(d => d.CurrentStatus == status)
            .ToList();
    }

    // 更新设备性能指标
    public void UpdateDevicePerformance(int deviceId, PerformanceMetrics metrics)
    {
        var device = _deviceCollection.FindById(deviceId);
        if (device != null)
        {
            device.Performance = metrics;
            _deviceCollection.Update(device);
        }
    }

    // 添加告警记录
    public void AddAlarmRecord(int deviceId, AlarmRecord alarm)
    {
        var device = _deviceCollection.FindById(deviceId);
        if (device != null)
        {
            device.AlarmHistory ??= new List<AlarmRecord>();
            device.AlarmHistory.Add(alarm);
            _deviceCollection.Update(device);
        }
    }
}

调用

C#
namespace App02
{
    internal class Program
    {
        static void Main(string[] args)
        {
            // 数据库路径（建议使用相对或绝对路径）  
            string databasePath = "DeviceDatabase.db";

            // 创建仓储实例  
            DeviceRepository repository = new DeviceRepository(databasePath);

            // 创建测试设备  
            DeviceInfo device1 = new DeviceInfo
            {
                DeviceName = "机器人001",
                DeviceModel = "RX-78-2",
                Manufacturer = "Gundam Corp",
                CurrentStatus = DeviceStatus.Running,
                Performance = new PerformanceMetrics
                {
                    OperationEfficiency = 95.5,
                    EnergyConsumption = 250.75,
                    TotalRunningHours = 1200
                },
                AlarmHistory = new List<AlarmRecord>()
            };

            DeviceInfo device2 = new DeviceInfo
            {
                DeviceName = "机器人002",
                DeviceModel = "MK-II",
                Manufacturer = "Gundam Tech",
                CurrentStatus = DeviceStatus.Maintenance,
                Performance = new PerformanceMetrics
                {
                    OperationEfficiency = 80.0,
                    EnergyConsumption = 300.25,
                    TotalRunningHours = 800
                },
                AlarmHistory = new List<AlarmRecord>()
            };

            // 插入设备  
            repository.InsertDevice(device1);
            repository.InsertDevice(device2);

            // 添加告警记录  
            repository.AddAlarmRecord(device1.Id, new AlarmRecord
            {
                Timestamp = DateTime.Now,
                AlarmType = "性能下降",
                Description = "温度异常",
                Severity = AlarmSeverity.Medium
            });

            // 查询运行中的设备  
            var runningDevices = repository.GetDevicesByStatus(DeviceStatus.Running);
            Console.WriteLine("运行中的设备:");
            foreach (var device in runningDevices)
            {
                Console.WriteLine($"设备名称: {device.DeviceName}");
                Console.WriteLine($"运行效率: {device.Performance.OperationEfficiency}%");
            }

            // 更新设备性能  
            repository.UpdateDevicePerformance(device2.Id, new PerformanceMetrics
            {
                OperationEfficiency = 85.5,
                EnergyConsumption = 280.0,
                TotalRunningHours = 900
            });

            Console.WriteLine("演示完成,请检查数据库文件");
        }
    }
}

测试类

C#
namespace App02.Tests
{
    public class DeviceRepositoryTests
    {
        private readonly DeviceRepository _repository;
        private readonly string _testDbPath;

        public DeviceRepositoryTests()
        {
            // 使用临时数据库路径  
            _testDbPath = Path.Combine(Path.GetTempPath(), $"test_{Guid.NewGuid()}.db");
            _repository = new DeviceRepository(_testDbPath);
        }

        [Fact]
        public void TestDeviceInsertion()
        {
            // 创建测试设备  
            var testDevice = new DeviceInfo
            {
                DeviceName = "工业机器人 #001",
                DeviceModel = "RX-250",
                Manufacturer = "RobotCorp",
                CurrentStatus = DeviceStatus.Running,
                Performance = new PerformanceMetrics
                {
                    OperationEfficiency = 95.5,
                    EnergyConsumption = 2.3,
                    TotalRunningHours = 1200
                }
            };

            // 插入设备  
            _repository.InsertDevice(testDevice);

            // 验证插入  
            var retrievedDevices = _repository.GetDevicesByStatus(DeviceStatus.Running);
            Assert.Single(retrievedDevices);
            Assert.Equal("工业机器人 #002", retrievedDevices[0].DeviceName);
        }

        [Fact]
        public void TestDevicePerformanceUpdate()
        {
            // 创建并插入初始设备  
            var testDevice = new DeviceInfo
            {
                DeviceName = "工业打印机 #002",
                CurrentStatus = DeviceStatus.Running
            };
            _repository.InsertDevice(testDevice);

            // 获取设备ID  
            var deviceId = _repository.GetDevicesByStatus(DeviceStatus.Running).First().Id;

            // 更新性能指标  
            var newMetrics = new PerformanceMetrics
            {
                OperationEfficiency = 88.7,
                EnergyConsumption = 1.9,
                TotalRunningHours = 850
            };
            _repository.UpdateDevicePerformance(deviceId, newMetrics);

            // 验证更新  
            var updatedDevices = _repository.GetDevicesByStatus(DeviceStatus.Running);
            Assert.Equal(88.7, updatedDevices[0].Performance.OperationEfficiency);
        }

        [Fact]
        public void TestAlarmRecordAddition()
        {
            // 创建并插入初始设备  
            var testDevice = new DeviceInfo
            {
                DeviceName = "CNC机床 #003",
                CurrentStatus = DeviceStatus.Error
            };
            _repository.InsertDevice(testDevice);

            // 获取设备ID  
            var deviceId = _repository.GetDevicesByStatus(DeviceStatus.Error).First().Id;

            // 添加告警记录  
            var alarmRecord = new AlarmRecord
            {
                Timestamp = DateTime.Now,
                AlarmType = "过热",
                Description = "设备温度超过安全阈值",
                Severity = AlarmSeverity.High
            };
            _repository.AddAlarmRecord(deviceId, alarmRecord);

            // 验证告警记录  
            var updatedDevices = _repository.GetDevicesByStatus(DeviceStatus.Error);
            Assert.Single(updatedDevices[0].AlarmHistory);
            Assert.Equal("过热", updatedDevices[0].AlarmHistory[0].AlarmType);
        }
    }
}

要运行这些测试，您需要：

• 安装 LiteDB NuGet 包
• 安装 xUnit 测试框架
• 确保已实现之前文章中定义的所有类（DeviceInfo、DeviceStatus等）

TestDeviceInsertion 测试方法

注意事项

1. 保持文档结构相对一致
2. 合理使用索引
3. 避免过深的嵌套结构
4. 定期维护数据库
5. 使用事务处理复杂操作
6. 定期压缩数据库

结语

LiteDB 为工业自动化领域的数据建模提供了极大的灵活性和便利性，通过面向文档的设计，可以轻松应对复杂多变的工业数据场景。