diff --git a/Src/Asp.NetCore2/MongoDbTest/UnitTest/QuerySelect.cs b/Src/Asp.NetCore2/MongoDbTest/UnitTest/QuerySelect.cs
index 84d7dc3ef..826939590 100644
--- a/Src/Asp.NetCore2/MongoDbTest/UnitTest/QuerySelect.cs
+++ b/Src/Asp.NetCore2/MongoDbTest/UnitTest/QuerySelect.cs
@@ -157,11 +157,13 @@ namespace MongoDbTest
                 }).ToList();
 
             var list17 = db.Queryable<Student>()  
+                .Where(it=>SqlFunc.Length(it.Name)>1)
                .Select(it => new
                {
                    name2=it.Name,
                    name = it.Name.Substring(0,1), 
                }).ToList();
+            if(list17.First().name2!="a2"||list17.First().name.Substring(0,1)!= list17.First().name) Cases.ThrowUnitError();
         }
         [SqlSugar.SugarTable("UnitStudent1231sds3z1")]
         public class Student : MongoDbBase