diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/Dm/SqlBuilder/DmExpressionContext.cs b/Src/Asp.NetCore2/SqlSugar/Realization/Dm/SqlBuilder/DmExpressionContext.cs
index 2e457f31c..ad55b0b93 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/Dm/SqlBuilder/DmExpressionContext.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/Dm/SqlBuilder/DmExpressionContext.cs
@@ -54,11 +54,11 @@ namespace SqlSugar
     }
     public partial class DmMethod : DefaultDbMethod, IDbMethods
     {
-        public override string IsNullOrEmpty(MethodCallExpressionModel model)
-        {
-            var parameter = model.Args[0];
-            return string.Format("( {0} IS NULL )", parameter.MemberName);
-        }
+        //public override string IsNullOrEmpty(MethodCallExpressionModel model)
+        //{
+        //    var parameter = model.Args[0];
+        //    return string.Format("( {0} IS NULL )", parameter.MemberName);
+        //}
         public override string WeekOfYear(MethodCallExpressionModel mode)
         {
             var parameterNameA = mode.Args[0].MemberName;