diff --git a/Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/SubqueryableN.cs b/Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/SubqueryableN.cs
index e7a251b0c..d22490899 100644
--- a/Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/SubqueryableN.cs
+++ b/Src/Asp.Net/SqlSugar/ExpressionsToSql/Subquery/SubqueryableN.cs
@@ -186,6 +186,10 @@ namespace SqlSugar
     }
     public class Subqueryable<T1, T2, T3, T4, T5, T6> : Subqueryable<T1> where T1 : class, new()
     {
+        public string SelectStringJoin(Func<T1, T2, T3, T4, T5,T6, string> expression, string separator)
+        {
+            return default(string);
+        }
         public new Subqueryable<T1, T2, T3, T4, T5,T6> AsWithAttr()
         {
             return this;
@@ -242,6 +246,10 @@ namespace SqlSugar
     }
     public class Subqueryable<T1, T2, T3, T4, T5> : Subqueryable<T1> where T1 : class, new()
     {
+        public string SelectStringJoin(Func<T1, T2, T3, T4,T5, string> expression, string separator)
+        {
+            return default(string);
+        }
         public new Subqueryable<T1, T2, T3, T4,T5> AsWithAttr()
         {
             return this;