PlayerRepository.java

// Copyright 2022 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.pingcap.dao;

import jakarta.persistence.LockModeType;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Lock;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface PlayerRepository extends JpaRepository<PlayerBean, Long> {
    /**
     * use HQL to query by page
     * @param pageable a pageable parameter required by hibernate
     * @return player list package by page message
     */
    @Query(value = "SELECT player_jpa FROM PlayerBean player_jpa")
    Page<PlayerBean> getPlayersByPage(Pageable pageable);

    /**
     * use SQL to query by limit, using named parameter
     * @param limit sql parameter
     * @return player list (max size by limit)
     */
    @Query(value = "SELECT * FROM player_jpa LIMIT :limit", nativeQuery = true)
    List<PlayerBean> getPlayersByLimit(@Param("limit") Integer limit);

    /**
     * query player and add a lock for update
     * @param id player id
     * @return player
     */
    @Lock(value = LockModeType.PESSIMISTIC_WRITE)
    @Query(value = "SELECT player FROM PlayerBean player WHERE player.id = :id")
    // @Query(value = "SELECT * FROM player_jpa WHERE id = :id FOR UPDATE", nativeQuery = true)
    PlayerBean getPlayerAndLock(@Param("id") Long id);
}