if there is just 1 route -> use that for a newly created station

src/admin/route/mod.rs

@@ -45,7 +45,11 @@ impl Route {
             .unwrap();
     }
 
-    async fn add_station(&self, db: &SqlitePool, station: &Station) -> Result<(), String> {
+    pub(crate) async fn add_station(
+        &self,
+        db: &SqlitePool,
+        station: &Station,
+    ) -> Result<(), String> {
         sqlx::query!(
             r#"
         INSERT INTO route_station (route_id, station_id, pos)

src/admin/station/mod.rs

@@ -80,10 +80,26 @@ impl Station {
 
     pub(crate) async fn create(db: &SqlitePool, name: &str) -> Result<(), String> {
         let code = generate_random_alphanumeric(8);
-        sqlx::query!("INSERT INTO station(name, pw) VALUES (?, ?)", name, code)
+        let station_id = sqlx::query!(
-            .execute(db)
+            "INSERT INTO station(name, pw) VALUES (?, ?) RETURNING id",
-            .await
+            name,
-            .map_err(|e| e.to_string())?;
+            code
+        )
+        .fetch_one(db)
+        .await
+        .map_err(|e| e.to_string())?;
+
+        let mut routes = Route::all(db).await.into_iter();
+        if let Some(route) = routes.next() {
+            if routes.next().is_none() {
+                // Just one route exists -> use it for new station
+                let station = Station::find_by_id(db, station_id.id)
+                    .await
+                    .expect("just created");
+
+                route.add_station(db, &station).await?;
+            }
+        }
         Ok(())
     }