完成Mqtt服务器添加功能

DMS.Infrastructure/Entities/DbMqttServer.cs

@@ -19,9 +19,9 @@ public class DbMqttServer
     public string ServerName { get; set; }
 
     /// <summary>
-    /// MQTT代理地址
+    /// MQTT服务器URL
     /// </summary>
-    public string BrokerAddress { get; set; }
+    public string ServerUrl { get; set; }
 
     /// <summary>
     /// 端口号
@@ -66,15 +66,18 @@ public class DbMqttServer
     /// <summary>
     /// 连接时间
     /// </summary>
+    [SugarColumn(IsNullable = true)]
     public DateTime? ConnectedAt { get; set; }
 
     /// <summary>
     /// 连接持续时间（秒）
     /// </summary>
+    [SugarColumn(IsNullable = true)]
     public long ConnectionDuration { get; set; }
 
     /// <summary>
     /// 消息格式
     /// </summary>
+    [SugarColumn(IsNullable = true)]
     public string MessageFormat { get; set; }
 }

DMS.Infrastructure/Services/MqttBackgroundService.cs

@@ -266,7 +266,7 @@ public class MqttBackgroundService : BackgroundService
 
         var options = new MqttClientOptionsBuilder()
                       .WithClientId(mqtt.ClientId)
-                      .WithTcpServer(mqtt.BrokerAddress, mqtt.Port)
+                      .WithTcpServer(mqtt.ServerUrl, mqtt.Port)
                       .WithCredentials(mqtt.Username, mqtt.Password)
                       .WithCleanSession()
                       .Build();