新增查询数据链接和检测是否可以链接数据库！

Falcon.SugarApi/DatabaseDefinitions/SugarDbContext.cs

@@ -2,6 +2,7 @@
 using SqlSugar;
 using System;
 using System.Collections.Generic;
+using System.Data;
 using System.Linq;
 using System.Text;
 
@@ -266,5 +267,15 @@ namespace Falcon.SugarApi.DatabaseDefinitions
         public DateTime DbDateTime {
             get => SqlFunc.GetDate();
         }
+
+        /// <summary>
+        /// 数据库链接
+        /// </summary>
+        public IDbConnection Connection => this.Ado.Connection;
+
+        /// <summary>
+        /// 是否可以成功连接数据库
+        /// </summary>
+        public bool Connected => this.Ado.IsValidConnection();
     }
 }