Improve error message when transaction is cancelled

src/dbs/executor.rs

@@ -112,7 +112,7 @@ impl<'a> Executor<'a> {
 			sql: v.sql,
 			time: v.time,
 			status: Status::Err,
-			detail: Some(format!("Transaction cancelled")),
+			detail: Some(format!("{}", Error::QueryCancelledError)),
 			result: None,
 		}
 	}

src/err/mod.rs

@@ -70,6 +70,9 @@ pub enum Error {
 		timer: Duration,
 	},
 
+	#[error("Query not executed due to cancelled transaction")]
+	QueryCancelledError,
+
 	#[error("Query not executed due to failed transaction")]
 	QueryExecutionError,