diff --git a/SqlServerTest/Demo/DbFirst.cs b/SqlServerTest/Demo/DbFirst.cs
index 063eba5c6..4de4fee6f 100644
--- a/SqlServerTest/Demo/DbFirst.cs
+++ b/SqlServerTest/Demo/DbFirst.cs
@@ -11,22 +11,22 @@ namespace OrmTest.Demo
         public static void Init()
         {
             var db = GetInstance();
-            ////Create all class
-            //db.DbFirst.CreateClassFile("c:\\Demo\\1");
+            //Create all class
+            db.DbFirst.CreateClassFile("c:\\Demo\\1");
 
-            ////Create student calsss
-            //db.DbFirst.Where("Student").CreateClassFile("c:\\Demo\\2");
-            ////Where(array)
+            //Create student calsss
+            db.DbFirst.Where("Student").CreateClassFile("c:\\Demo\\2");
+            //Where(array)
 
-            ////Mapping name
-            //db.MappingTables.Add("ClassStudent", "Student");
-            //db.DbFirst.Where("Student").CreateClassFile("c:\\Demo\\3");
+            //Mapping name
+            db.MappingTables.Add("ClassStudent", "Student");
+            db.DbFirst.Where("Student").CreateClassFile("c:\\Demo\\3");
 
-            ////Remove mapping
-            //db.MappingTables.Clear();
+            //Remove mapping
+            db.MappingTables.Clear();
 
-            //Create class with default value
-            db.DbFirst.IsCreateDefaultValue().CreateClassFile("c:\\Demo\\4");
+            Create class with default value
+            db.DbFirst.IsCreateDefaultValue().CreateClassFile("c:\\Demo\\4","Demo.Models");
         }
     }
 }
\ No newline at end of file
diff --git a/SqlSugar/Abstract/DbFirstProvider/DbFirstProvider.cs b/SqlSugar/Abstract/DbFirstProvider/DbFirstProvider.cs
index 524ca0039..60e19db06 100644
--- a/SqlSugar/Abstract/DbFirstProvider/DbFirstProvider.cs
+++ b/SqlSugar/Abstract/DbFirstProvider/DbFirstProvider.cs
@@ -178,6 +178,9 @@ namespace SqlSugar
                             }
                         }
                     }
+                    if (!columns.Any(it => it.DefaultValue != null)) {
+                        ConstructorText = null;
+                    }
                     classText = classText.Replace(DbFirstTemplate.KeyConstructor, ConstructorText);
                     classText = classText.Replace(DbFirstTemplate.KeyPropertyName, null);
                     result.Add(className, classText);