fix: Use incremental ID

heromodels/examples/simple_model_example.rs

@@ -1,3 +1,4 @@
+use heromodels::db::{Collection, Db};
 use heromodels_core::{BaseModelData, Model};
 use heromodels_derive::model;
 use serde::{Deserialize, Serialize};
@@ -15,16 +16,36 @@ fn main() {
     println!("Hero Models - Simple Model Example");
     println!("==================================");
 
+    // Create a new DB instance, reset before every run
+    let db_path = "/tmp/ourdb_simple_model_example";
+    let db = heromodels::db::hero::OurDB::new(db_path, true).expect("Can create DB");
+
     // Example usage of the generated implementation
     println!("SimpleUser DB Prefix: {}", SimpleUser::db_prefix());
 
+    // Create a new user with ID 0 (will be auto-generated when saved)
     let user = SimpleUser {
         base_data: BaseModelData::new(),
         login: "johndoe".to_string(),
         full_name: "John Doe".to_string(),
     };
 
-    println!("\nSimpleUser ID: {}", user.get_id());
-    println!("SimpleUser DB Keys: {:?}", user.db_keys());
+    println!("\nBefore saving - SimpleUser ID: {}", user.get_id());
+    println!("Before saving - SimpleUser DB Keys: {:?}", user.db_keys());
+
+    // Save the user to the database
+    let collection = db.collection::<SimpleUser>().expect("can open user collection");
+    let (user_id, saved_user) = collection.set(&user).expect("can save user");
+
+    println!("\nAfter saving - SimpleUser ID: {}", saved_user.get_id());
+    println!("After saving - SimpleUser DB Keys: {:?}", saved_user.db_keys());
+    println!("Returned ID: {}", user_id);
+
+    // Verify that the ID was auto-generated
+    assert_eq!(saved_user.get_id(), user_id);
+    assert_ne!(saved_user.get_id(), 0);
+
+    println!("\nExample finished. DB stored at {}", db_path);
+    println!("To clean up, you can manually delete the directory: {}", db_path);
 }