MyBatis-Plus Service CRUD 常用方法 Demo

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本文介绍了MyBatis-Plus中Service层进行CRUD操作的常用方法，包括根据columnMap查询、使用Wrapper查询列表、通过ID获取单个实体以及运用Wrapper获取唯一记录。

1.List

1.1 查询（根据 columnMap 条件查询）
Collection<T> listByMap(Map<String, Object> columnMap);

Map colMap = new HashMap();
colMap.put("orderNo", "fsdfsdfsdfsad1333");
colMap.put("orderType", "WK");
Collection<FastOrder> fastOrderColl = listByMap(colMap);//返回多条FastOrder实体对象
System.out.println("fastOrderColl :"+fastOrderColl );

// 可以使用get(index)获取第n个实体

FastOrder fastorder = fastOrderColl.get(0);//获取第一个

1.2查询列表

List<T> list(Wrapper<T> queryWrapper);

// SELECT * FROM fast_order WHERE isBack='0' AND status IN('10B', '10C') AND createTime > DATE_SUB(NOW(), INTERVAL 30 MINUTE) AND createTime < DATE_SUB(NOW(), INTERVAL 10 MINUTE) LIMIT 500
QueryWrapper queryWrapper = new QueryWrapper();
queryWrapper.eq("isBack", "0");
queryWrapper.in("status", "10B","10C");
queryWrapper.gt("createTime",  LocalDateTime.now().minusMinutes(30));
queryWrapper.lt("createTime", LocalDateTime.now().minusMinutes(10));
queryWrapper.last("limit 500");
List<FastOrder> fastOrderT = list(queryWrapper);
System.out.println("fastOrderT:"+fastOrderT);

2.Get

2.1 根据ID查询

T getById(Serializable id);

FastOrder fastOrderT = getById("1");//返回一条FastOrder 实体对象
System.out.println("fastOrderT:"+fastOrderT);

2.2 // 根据 Wrapper，查询一条记录。结果集，如果是多个会抛出异常，随机取一条加上限制条件 wrapper.last("LIMIT 1")

T getOne(Wrapper<T> queryWrapper);

QueryWrapper queryWrapper = new QueryWrapper();
queryWrapper.eq("orderNo","fsdfsdfsdfsad1333");
// queryWrapper.last("LIMIT 1");
FastOrder fastOrder = getOne(queryWrapper);
System.out.println("fastOrder:"+fastOrder);

3.update

public boolean upDateStatusByorderNo(String orderNo){
        UpdateWrapper<UserOrderPayment> updateWrapper = new UpdateWrapper<>();
        updateWrapper.eq("orderNo",orderNo);

        UserOrderPayment userOrderPayment = new UserOrderPayment();
        userOrderPayment.setStatus("10D");
        boolean userOrderPaymentrow = update(userOrderPayment, updateWrapper);
        return userOrderPaymentrow;
    }