diff --git a/examples/async-std/src/example_cake.rs b/examples/async-std/src/example_cake.rs
index 6820be61..8f704f3b 100644
--- a/examples/async-std/src/example_cake.rs
+++ b/examples/async-std/src/example_cake.rs
@@ -13,17 +13,6 @@ pub enum Relation {
     Fruit,
 }
 
-impl ColumnTrait for Column {
-    type EntityName = Entity;
-
-    fn def(&self) -> ColumnDef {
-        match self {
-            Self::Id => ColumnType::Integer.def(),
-            Self::Name => ColumnType::String(None).def(),
-        }
-    }
-}
-
 impl RelationTrait for Relation {
     fn def(&self) -> RelationDef {
         match self {
diff --git a/sea-orm-macros/src/derives/entity_model.rs b/sea-orm-macros/src/derives/entity_model.rs
index 10aabd59..13188495 100644
--- a/sea-orm-macros/src/derives/entity_model.rs
+++ b/sea-orm-macros/src/derives/entity_model.rs
@@ -35,7 +35,7 @@ pub fn expand_derive_entity_model(data: Data, attrs: Vec<Attribute>) -> syn::Res
             pub struct Entity;
             
             impl sea_orm::prelude::EntityName for Entity {
-                fn schema_name(&self) -> &str {
+                fn schema_name(&self) -> Option<&str> {
                     #schema_name
                 }