Mybatis-Plus 条件构造器的使用

AbstractWrapper：

  /**
     * 使用构造器 条件查询
     */
    @Test
    public void selectOne() {
        AbstractWrapper wrapper = new QueryWrapper<>();
        wrapper.eq("nick_name", "测试一下");

        //区间查询
        //wrapper.between("member_id",1,90);
        MemberInfo result = memberInfoMapper.selectOne(wrapper);
        System.out.println(result);
    }

QueryWrapper

/**
     * 排序查询
     */
    @Test
    public void selectOrderList() {
        QueryWrapper<ShippingAddress> wrapper = new QueryWrapper<>();

        //根据id排序  orderByAsc:升序     orderByDesc:降序
        wrapper.orderByAsc("member_id");
        List<ShippingAddress> addressList = shippingAddressMapper.selectList(wrapper);
        addressList.forEach(System.out::println);
    }

    /**
     * 模糊查询
     */
    @Test
    public void selectList() {
        QueryWrapper<ShippingAddress> wrapper = new QueryWrapper<>();
        //模糊包含
        //wrapper.like("detail_address","广东");

        //右模糊查询  向左查起
        wrapper.likeRight("detail_address", "广");
        List<Map<String, Object>> map = shippingAddressMapper.selectMaps(wrapper);
        map.forEach(System.out::println);
    }

    /**
     * 条件查询 
     */
    @Test
    public void selectObjs() {
        QueryWrapper<ShippingAddress> wrapper = new QueryWrapper<>();

        //查询id <100的数据   select * from shipping_address where member_id in (你的sql)
        wrapper.inSql("member_id", "select member_id from shipping_address where member_id<100");
        List<Object> objectList = shippingAddressMapper.selectObjs(wrapper);
        System.out.println(objectList);
    }

UpdateWrapper

    /**
     * 编辑信息
     */
    @Test
    public void update() {
        MemberInfo memberInfo = new MemberInfo();

        UpdateWrapper updateWrapper = new UpdateWrapper();
        memberInfo.setMemberId(memberInfo.getMemberId());
        updateWrapper.set("nick_name", "程序图");
        //updateWrapper.setSql("nick_name = '老李头'");
        memberInfoMapper.update(memberInfo, updateWrapper);
    }

个别参数说明:

/**
     * eq：等于    ne： 不等于
     * gt：大于    ge：大于或等于
     * lt：小于    le： 小或于或等于
     * like：模糊查询（包含）    notLike(不包含)  likeLeft：模糊左查询   likeRight：模糊右查询
     * isNull：为空   isNoNull:不为空
     * orderByAsc:升序    orderByDesc:降序
     * between:区间查询    age between 18 and 30
     */

详细文档请前往pius官网或者MyBatis-Plus v3.3.2 使用教程

https://www.bookstack.cn/read/mybatis-3.3.2/%E5%BF%AB%E9%80%9F%E5%85%A5%E9%97%A8.md