- 增加 DbContext/Repository 比较变化方法 CompareState；

FreeSql.DbContext/Repository/Repository/BaseRepository.cs

@@ -127,6 +127,7 @@ namespace FreeSql
             return this;
         }
         public void FlushState() => _dbset.FlushState();
+        public Dictionary<string, object[]> CompareState(TEntity newdata) => _dbset.CompareState(newdata);
 
         public virtual TEntity InsertOrUpdate(TEntity entity)
         {

FreeSql.DbContext/Repository/Repository/IBaseRepository.cs

@@ -58,6 +58,12 @@ namespace FreeSql
         /// </summary>
         /// <param name="data"></param>
         IBaseRepository<TEntity> AttachOnlyPrimary(TEntity data);
+        /// <summary>
+        /// 比较实体，计算出值发生变化的属性，以及属性变化的前后值
+        /// </summary>
+        /// <param name="newdata">最新的实体对象，它将与附加实体的状态对比</param>
+        /// <returns></returns>
+        Dictionary<string, object[]> CompareState(TEntity newdata);
 
         int Update(TEntity entity);
         int Update(IEnumerable<TEntity> entitys);