clean families; Fixes #1171

src/model/family.rs

@@ -93,6 +93,19 @@ GROUP BY family.id;"
     }
 
     pub async fn clean_families_without_members(db: &SqlitePool) {
+        sqlx::query(
+            "UPDATE user SET family_id = NULL
+WHERE family_id IN (
+    SELECT family_id FROM user
+    WHERE family_id IS NOT NULL
+    GROUP BY family_id
+    HAVING COUNT(*) = 1
+);",
+        )
+        .execute(db)
+        .await
+        .unwrap();
+
         sqlx::query(
             "DELETE FROM family
 WHERE id NOT IN (