Add update and get-by-tag for schedules

src/db/errors.rs

@@ -10,6 +10,7 @@ pub enum DatabaseError {
     InsertGetError,
     NotFound,
     Protected,
+    UpdateError(diesel::result::Error),
 }
 
 impl DatabaseError {
@@ -45,6 +46,7 @@ impl From<&DatabaseError> for String {
             DatabaseError::NotFound => String::from("model was not found in database"),
             DatabaseError::DeleteError => String::from("error on deleting from database"),
             DatabaseError::Protected => String::from("model is protected"),
+            DatabaseError::UpdateError(_) => String::from("error on updating the model"),
         }
     }
 }