show guest km, Fixes #41

src/model/stat.rs

@@ -36,6 +36,36 @@ ORDER BY rowed_km DESC;
         .collect()
     }
 
+    pub async fn guest(db: &SqlitePool, year: Option<i32>) -> Stat {
+        let year = match year {
+            Some(year) => year,
+            None => chrono::Utc::now().year(),
+        };
+        //TODO: switch to query! macro again (once upgraded to sqlite 3.42 on server)
+        let rowed_km = sqlx::query(&format!(
+            "
+SELECT SUM((b.amount_seats - COALESCE(m.member_count, 0)) * l.distance_in_km) as total_guest_km
+FROM logbook l
+JOIN boat b ON l.boat_id = b.id
+LEFT JOIN (
+    SELECT logbook_id, COUNT(*) as member_count
+    FROM rower
+    GROUP BY logbook_id
+) m ON l.id = m.logbook_id
+WHERE l.distance_in_km IS NOT NULL AND l.arrival LIKE '{year}-%' AND b.name != 'Externes Boot';
+"
+        ))
+        .fetch_one(db)
+        .await
+        .unwrap()
+        .get::<i64, usize>(0);
+
+        Stat {
+            name: "Gäste".into(),
+            rowed_km: rowed_km as i32,
+        }
+    }
+
     pub async fn people(db: &SqlitePool, year: Option<i32>) -> Vec<Stat> {
         let year = match year {
             Some(year) => year,