osu: make save command use interaction

youmubot-db-sql/src/lib.rs

@@ -36,9 +36,27 @@ pub mod errors {
     #[derive(thiserror::Error, Debug)]
     pub enum Error {
         #[error("sqlx error: {:?}", .0)]
-        SQLx(#[from] sqlx::Error),
+        SQLx(sqlx::Error),
         #[error("sqlx migration error: {:?}", .0)]
         Migration(#[from] sqlx::migrate::MigrateError),
+        #[error("values already existed for: {}", .0)]
+        Duplicate(String),
+    }
+
+    impl From<sqlx::Error> for Error {
+        fn from(value: sqlx::Error) -> Self {
+            match value {
+                // if we can match a constraint error, give it a special case.
+                sqlx::Error::Database(database_error) => {
+                    let msg = database_error.message();
+                    match msg.strip_prefix("UNIQUE constraint failed: ") {
+                        Some(con) => Error::Duplicate(con.to_owned()),
+                        None => Error::SQLx(sqlx::Error::Database(database_error)),
+                    }
+                }
+                e => Error::SQLx(e),
+            }
+        }
     }
 }