diff --git a/Src/Asp.NetCore2/SqlSugar/Realization/Dm/SqlBuilder/DmExpressionContext.cs b/Src/Asp.NetCore2/SqlSugar/Realization/Dm/SqlBuilder/DmExpressionContext.cs
index 938718245..2e457f31c 100644
--- a/Src/Asp.NetCore2/SqlSugar/Realization/Dm/SqlBuilder/DmExpressionContext.cs
+++ b/Src/Asp.NetCore2/SqlSugar/Realization/Dm/SqlBuilder/DmExpressionContext.cs
@@ -54,6 +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 WeekOfYear(MethodCallExpressionModel mode)
         {
             var parameterNameA = mode.Args[0].MemberName;