fix

src/tournament/tournament.service.ts

@@ -397,18 +397,24 @@ export class TournamentService extends CrudService(Tournament, {
     updates: { id: T; seq: number }[],
   ) {
     if (updates.length) {
-      await this.repo.manager
-        .createQueryBuilder()
-        .update(Participant)
-        .set({
-          seq: () => `
+      if (updates.length > 1) {
+        await this.repo.manager
+          .createQueryBuilder()
+          .update(Participant)
+          .set({
+            seq: () => `
           CASE id
           ${updates.map((p) => `WHEN ${p.id} THEN ${p.seq}`).join('\n')}
           END
         `,
-        })
-        .whereInIds(updates.map((p) => p.id))
-        .execute();
+          })
+          .whereInIds(updates.map((p) => p.id))
+          .execute();
+      } else {
+        await this.repo.manager.update(Participant, updates[0].id, {
+          seq: updates[0].seq,
+        });
+      }
     }
 
     return new GenericReturnMessageDto(