Fix bug children's foreign key not deleted

backend/src/endpoint/contest.rs

@@ -1,9 +1,9 @@
 use super::*;
-
 use crate::entity::{
     contest::{Paginator, *},
-    *,
+    problem, *,
 };
+use sea_orm::sea_query::Expr;
 
 use grpc::backend::contest_server::*;
 
@@ -238,6 +238,8 @@ impl Contest for ArcServer {
         let (auth, req) = self.rate_limit(req).in_current_span().await?;
 
         req.get_or_insert(|req| async move {
+            let txn = self.db.begin().await?;
+
             let result = Entity::delete_by_id(req.id)
                 .with_auth(&auth)
                 .write()?
@@ -246,12 +248,20 @@ impl Contest for ArcServer {
                 .await
                 .map_err(Into::<Error>::into)?;
 
+            problem::Entity::update_many()
+                .col_expr(problem::Column::ContestId, Expr::value(Value::Int(None)))
+                .filter(crate::entity::testcase::Column::ProblemId.eq(req.id))
+                .exec(&txn)
+                .instrument(info_span!("remove_child"))
+                .await?;
+
+            txn.commit().await.map_err(|_| Error::Retry)?;
+
             if result.rows_affected == 0 {
-                Err(Error::NotInDB)
-            } else {
-                tracing::info!(counter.contest = -1, id = req.id);
-                Ok(())
+                return Err(Error::NotInDB);
             }
+            tracing::info!(counter.contest = -1, id = req.id);
+            Ok(())
         })
         .await
         .with_grpc()

backend/src/endpoint/problem.rs

@@ -1,7 +1,8 @@
 use super::*;
 use grpc::backend::problem_server::*;
+use sea_orm::sea_query::Expr;
 
-use crate::entity::{contest, problem::Paginator, problem::*};
+use crate::entity::{contest, problem::Paginator, problem::*, testcase};
 
 impl<'a> From<WithAuth<'a, Model>> for ProblemFullInfo {
     fn from(value: WithAuth<'a, Model>) -> Self {
@@ -191,17 +192,28 @@ impl Problem for ArcServer {
     async fn remove(&self, req: Request<RemoveRequest>) -> Result<Response<()>, Status> {
         let (auth, req) = self.rate_limit(req).in_current_span().await?;
         req.get_or_insert(|req| async move {
+            let txn = self.db.begin().await?;
+
             let result = Entity::delete_by_id(req.id)
                 .with_auth(&auth)
                 .write()?
-                .exec(self.db.deref())
+                .exec(&txn)
                 .instrument(info_span!("remove").or_current())
-                .await
-                .map_err(Into::<Error>::into)?;
+                .await?;
+
+            testcase::Entity::update_many()
+                .col_expr(testcase::Column::ProblemId, Expr::value(Value::Int(None)))
+                .filter(testcase::Column::ProblemId.eq(req.id))
+                .exec(&txn)
+                .instrument(info_span!("remove_child"))
+                .await?;
+
+            txn.commit().await.map_err(|_| Error::Retry)?;
 
             if result.rows_affected == 0 {
                 return Err(Error::NotInDB);
             }
+            tracing::info!(count.problem = -1, id = req.id);
             Ok(())
         })
         .await

backend/src/util/error.rs

@@ -33,8 +33,6 @@ pub enum Error {
     Unreachable(&'static str),
     #[error("Number too large(or small)")]
     NumberTooLarge,
-    // #[error("Buffer `{0}` too large")]
-    // BufferTooLarge(&'static str),
     #[error("`{0}` Already exist")]
     AlreadyExist(&'static str),
     #[error("require permission `{0}`")]
@@ -47,6 +45,8 @@ pub enum Error {
     Judger(#[from] judger::Error),
     #[error("token error: `{0}`")]
     Token(#[from] token::Error),
+    #[error("retry later")]
+    Retry,
 }
 
 impl From<sea_orm::DbErr> for Error {
@@ -103,14 +103,15 @@ impl From<Error> for Status {
             Error::Image(x) => report_internal!(error, "{}", x),
             Error::Judger(x) => x.into(),
             Error::Token(x) => x.into(),
+            Error::Retry => Status::aborted("Should retry"),
         }
     }
 }
 
 /// Tracing information for error
 ///
 /// useful to log the tracing information to client
-/// without exposing the server's internal erro
+/// without exposing the server's internal error
 pub struct Tracing {
     trace_id: TraceId,
     span_id: SpanId,