diff --git a/Src/Asp.NetCore2/SqlSugar/Abstract/FastestProvider/FastBuilder.cs b/Src/Asp.NetCore2/SqlSugar/Abstract/FastestProvider/FastBuilder.cs
index a4da1f67c..67291446c 100644
--- a/Src/Asp.NetCore2/SqlSugar/Abstract/FastestProvider/FastBuilder.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Abstract/FastestProvider/FastBuilder.cs
@@ -48,7 +48,7 @@ namespace SqlSugar
             dt.TableName = "#temp";
         }
 
-        public async virtual Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns, List<T> datas)
+        public async virtual Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns, List<T> datas) where T : class, new()
         {
             var result = 0;
             await this.Context.Utilities.PageEachAsync(datas,2000,async pageItems =>
diff --git a/Src/Asp.NetCore2/SqlSugar/Interface/IFastBuilder.cs b/Src/Asp.NetCore2/SqlSugar/Interface/IFastBuilder.cs
index 144799134..d1e0d17a4 100644
--- a/Src/Asp.NetCore2/SqlSugar/Interface/IFastBuilder.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Interface/IFastBuilder.cs
@@ -18,6 +18,6 @@ namespace SqlSugar
         Task<int> ExecuteBulkCopyAsync(DataTable dt);
         Task CreateTempAsync<T>(DataTable dt) where T : class, new();
         void CloseDb();
-        Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns,List<T> datas);
+        Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns,List<T> datas) where T : class, new();
     }
 }
diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/SqlBuilder/OracleFastBuilder.cs b/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/SqlBuilder/OracleFastBuilder.cs
index 37985ce30..a1ca15684 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/SqlBuilder/OracleFastBuilder.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/Oracle/SqlBuilder/OracleFastBuilder.cs
@@ -67,7 +67,7 @@ namespace SqlSugar
 
         }
 
-        public override Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns,List<T> datas)
+        public override Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns,List<T> datas) where T : class 
         {
             Check.Exception(this.entityInfo.Columns.Any(it => it.OracleSequenceName.HasValue()), "The BulkMerge method cannot be used for  sequence", "BulkMerge方法不能用序列");
             var sqlBuilder = this.Context.Queryable<object>().SqlBuilder;
diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/SqlServer/SqlBuilder/SqlServerFastBuilder.cs b/Src/Asp.NetCore2/SqlSugar/Realization/SqlServer/SqlBuilder/SqlServerFastBuilder.cs
index 4a418aeb2..7d4d50398 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/SqlServer/SqlBuilder/SqlServerFastBuilder.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/SqlServer/SqlBuilder/SqlServerFastBuilder.cs
@@ -66,7 +66,7 @@ namespace SqlSugar
             copy.BulkCopyTimeout = this.Context.Ado.CommandTimeOut;
             return copy;
         }
-        public override Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns, List<T> datas)
+        public override Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns, List<T> datas) where  T : class 
         {
             var sqlBuilder = this.Context.Queryable<object>().SqlBuilder;
             var insertColumns = entityInfo.Columns
diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/Sqlite/SqlBuilder/SqliteFastBuilder.cs b/Src/Asp.NetCore2/SqlSugar/Realization/Sqlite/SqlBuilder/SqliteFastBuilder.cs
index 44b4736c3..40030431d 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/Sqlite/SqlBuilder/SqliteFastBuilder.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/Sqlite/SqlBuilder/SqliteFastBuilder.cs
@@ -176,7 +176,7 @@ namespace SqlSugar
             return result;
         }
 
-        public async  Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns, List<T> datas)
+        public async  Task<int> Merge<T>(DataTable dt, EntityInfo entityInfo, string[] whereColumns, string[] updateColumns, List<T> datas) where T : class, new()
         {
             var result = 0;
             await this.Context.Utilities.PageEachAsync(datas, 2000, async pageItems =>