diff --git a/Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/DbMethods/DefaultDbMethod.cs b/Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/DbMethods/DefaultDbMethod.cs
index dde8a03e8..ff3180088 100644
--- a/Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/DbMethods/DefaultDbMethod.cs
+++ b/Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/DbMethods/DefaultDbMethod.cs
@@ -25,7 +25,7 @@ namespace SqlSugar
         public virtual string HasValue(MethodCallExpressionModel model)
         {
             var parameter = model.Args[0];
-            return string.Format("( {0}<>'' AND {0} IS NOT NULL )", parameter.MemberName);
+            return string.Format("({0} IS NOT NULL )", parameter.MemberName);
         }
 
         public virtual string HasNumber(MethodCallExpressionModel model)
diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/SqlServer/SqlBuilder/SqlServerQueryBuilder.cs b/Src/Asp.NetCore2/SqlSugar/Realization/SqlServer/SqlBuilder/SqlServerQueryBuilder.cs
index c63cd4ea1..331cceaba 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/SqlServer/SqlBuilder/SqlServerQueryBuilder.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/SqlServer/SqlBuilder/SqlServerQueryBuilder.cs
@@ -78,8 +78,13 @@ namespace SqlSugar
                 if (this.OrderByValue.IsNullOrEmpty())
                 {
                     result += " ORDER BY GETDATE() ";
+                    if(this.OldSql.HasValue())
+                      this.OldSql += " ORDER BY GETDATE() ";
                 }
                 result += this.Offset;
+
+                if (this.OldSql.HasValue())
+                    this.OldSql += this.Offset;
             }
             result = GetSqlQuerySql(result);
             return result;
diff --git a/Src/Asp.NetCore2/SqlSugar/SimpleClient.cs b/Src/Asp.NetCore2/SqlSugar/SimpleClient.cs
index 6cba59f2f..1dee4c5cf 100644
--- a/Src/Asp.NetCore2/SqlSugar/SimpleClient.cs
+++ b/Src/Asp.NetCore2/SqlSugar/SimpleClient.cs
@@ -102,7 +102,7 @@ namespace SqlSugar
         {
             return Context.Queryable<T>().Single(whereExpression);
         }
-        public T GetFirst(Expression<Func<T, bool>> whereExpression) 
+        public virtual T GetFirst(Expression<Func<T, bool>> whereExpression) 
         {
             return Context.Queryable<T>().First(whereExpression);
         }
@@ -232,7 +232,7 @@ namespace SqlSugar
         {
             return Context.Queryable<T>().SingleAsync(whereExpression);
         }
-        public Task<T> GetFirstAsync(Expression<Func<T, bool>> whereExpression)
+        public virtual Task<T> GetFirstAsync(Expression<Func<T, bool>> whereExpression)
         {
             return Context.Queryable<T>().FirstAsync(whereExpression);
         }
diff --git a/Src/Asp.NetCore2/SqlSugar/Utilities/DataTableExtensions.cs b/Src/Asp.NetCore2/SqlSugar/Utilities/DataTableExtensions.cs
index 2a74d7300..17425ce53 100644
--- a/Src/Asp.NetCore2/SqlSugar/Utilities/DataTableExtensions.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Utilities/DataTableExtensions.cs
@@ -86,7 +86,7 @@ namespace SqlSugar
             if (rowSelector.Body is MemberExpression)
                 rowName = ((MemberExpression)rowSelector.Body).Member.Name;
             else
-                rowName = string.Join(UtilConstants.ReplaceKey, ((NewExpression)rowSelector.Body).Arguments.Select(it => it as MemberExpression).Select(it => it.Member.Name));
+                rowName = "Group_"+string.Join("_", ((NewExpression)rowSelector.Body).Arguments.Select(it => it as MemberExpression).Select(it => it.Member.Name));
             var columns = source.Select(columnSelector).Distinct();
 
             cols = (new[] { rowName }).Concat(columns.Select(x => x.ToString())).ToList();