Introduce ARITY to PrimaryKeyTrait

examples/basic/src/example_cake_filling.rs

@@ -40,6 +40,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 2;
+
     type ValueType = (i32, i32);
 
     fn auto_increment() -> bool {

examples/basic/src/example_filling.rs

@@ -38,6 +38,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

examples/basic/src/example_fruit.rs

@@ -42,6 +42,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

issues/1599/entity/src/cake_filling.rs

@@ -28,6 +28,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 2;
+
     type ValueType = (i32, i32);
 
     fn auto_increment() -> bool {

issues/1599/entity/src/filling.rs

@@ -39,6 +39,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/src/entity/writer.rs

@@ -561,8 +561,12 @@ impl EntityWriter {
     pub fn gen_impl_primary_key(entity: &Entity, date_time_crate: &DateTimeCrate) -> TokenStream {
         let primary_key_auto_increment = entity.get_primary_key_auto_increment();
         let value_type = entity.get_primary_key_rs_type(date_time_crate);
+        let primary_key_len = entity.primary_keys.len();
+        let arity = proc_macro2::Literal::usize_unsuffixed(primary_key_len);
         quote! {
             impl PrimaryKeyTrait for PrimaryKey {
+                const ARITY: usize = #arity;
+
                 type ValueType = #value_type;
 
                 fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded/cake.rs

@@ -29,6 +29,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded/cake_filling.rs

@@ -30,6 +30,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 2;
+
     type ValueType = (i32, i32);
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded/cake_filling_price.rs

@@ -32,6 +32,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 2;
+
     type ValueType = (i32, i32);
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded/cake_with_double.rs

@@ -31,6 +31,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded/cake_with_float.rs

@@ -31,6 +31,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded/child.rs

@@ -31,7 +31,10 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
+
     fn auto_increment() -> bool {
         true
     }

sea-orm-codegen/tests/expanded/collection.rs

@@ -31,7 +31,10 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
+
     fn auto_increment() -> bool {
         true
     }

sea-orm-codegen/tests/expanded/collection_float.rs

@@ -31,7 +31,10 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
+
     fn auto_increment() -> bool {
         true
     }

sea-orm-codegen/tests/expanded/filling.rs

@@ -29,6 +29,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded/fruit.rs

@@ -31,6 +31,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded/parent.rs

@@ -30,7 +30,10 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 2;
+
     type ValueType = (i32, i32);
+
     fn auto_increment() -> bool {
         false
     }

sea-orm-codegen/tests/expanded/rust_keyword.rs

@@ -51,6 +51,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded/vendor.rs

@@ -33,6 +33,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_attributes/cake_multiple.rs

@@ -31,6 +31,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_attributes/cake_none.rs

@@ -29,6 +29,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_attributes/cake_one.rs

@@ -30,6 +30,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_derives/cake_multiple.rs

@@ -29,6 +29,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_derives/cake_none.rs

@@ -29,6 +29,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_derives/cake_one.rs

@@ -29,6 +29,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_schema_name/cake.rs

@@ -33,6 +33,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_schema_name/cake_filling.rs

@@ -34,6 +34,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 2;
+
     type ValueType = (i32, i32);
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_schema_name/cake_filling_price.rs

@@ -36,6 +36,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 2;
+
     type ValueType = (i32, i32);
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_schema_name/cake_with_double.rs

@@ -35,6 +35,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_schema_name/cake_with_float.rs

@@ -35,6 +35,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_schema_name/child.rs

@@ -35,7 +35,10 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
+
     fn auto_increment() -> bool {
         true
     }

sea-orm-codegen/tests/expanded_with_schema_name/collection.rs

@@ -35,7 +35,10 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
+
     fn auto_increment() -> bool {
         true
     }

sea-orm-codegen/tests/expanded_with_schema_name/collection_float.rs

@@ -35,7 +35,10 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
+
     fn auto_increment() -> bool {
         true
     }

sea-orm-codegen/tests/expanded_with_schema_name/filling.rs

@@ -33,6 +33,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_schema_name/fruit.rs

@@ -35,6 +35,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_schema_name/parent.rs

@@ -34,7 +34,10 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 2;
+
     type ValueType = (i32, i32);
+
     fn auto_increment() -> bool {
         false
     }

sea-orm-codegen/tests/expanded_with_schema_name/rust_keyword.rs

@@ -55,6 +55,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_schema_name/vendor.rs

@@ -37,6 +37,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_serde/cake_both.rs

@@ -31,6 +31,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_serde/cake_deserialize.rs

@@ -31,6 +31,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_serde/cake_none.rs

@@ -29,6 +29,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {

sea-orm-codegen/tests/expanded_with_serde/cake_serialize.rs

@@ -30,6 +30,8 @@ pub enum PrimaryKey {
 }
 
 impl PrimaryKeyTrait for PrimaryKey {
+    const ARITY: usize = 1;
+
     type ValueType = i32;
 
     fn auto_increment() -> bool {