spring-data-jpa查询语句的书写实例小计

//查询语句
List<AuctionLot> alots = auctionLotRepository.findAllByAuctionIdAndAucIdIsNotNullAndIsOffcourtIsNullOrderByOrderNum(auctionId);

1.auctionId属性与传入的值相等


2.aucId属性不能为null


3.isOffcourt属性为null


4.根据orderNum排序

以上，查询语句和以下效果一样

Specification<AuctionLot> spec = (root, query, cb) -> {
            List<Predicate> predicates = new ArrayList<Predicate>();
            
            Predicate predicate = cb.equal(root.get(AuctionLot_.auctionId), auctionId);
            predicates.add(predicate);
            Predicate predicate1 = cb.isNotNull(root.get(AuctionLot_.aucId));
            predicates.add(predicate1);
            Predicate predicate2 = cb.notEqual(root.get(AuctionLot_.isOffcourt), Integer.valueOf(1));
            predicates.add(predicate2);
            query.orderBy(cb.desc(root.get(AuctionLot_.orderNum)));// 根据出价时间倒序排列
            if (!predicates.isEmpty()) {
                return cb.and(predicates.toArray(new Predicate[0]));
            } else {
                return null;
            }
        };
        
        List<AuctionLot> alots = auctionLotRepository.findAll(spec);