//查询所有

 List<PmsProduct> list1 = pmsProductService.list(new QueryWrapper<PmsProduct>());
1
//根据条件查询 eq
 List<PmsProduct> list2 = pmsProductService.list(new QueryWrapper<PmsProduct>().eq("id",2));
1
//关键字查询 like // 左 likelift %t ，右 likeRight t% //notLike不包含
 List<PmsProduct> list3 = pmsProductService.list(new QueryWrapper<PmsProduct>().eq("id",2).like("name","小王"));
1
//排序 orderBy
 List<PmsProduct> list4 = pmsProductService.list(new QueryWrapper<PmsProduct>().eq("id",2).like("name","小王").orderByDesc("age"));
1
//不等于 ne 大于gt 大于等于ge 小于lt
 List<PmsProduct> list5 = pmsProductService.list(new QueryWrapper<PmsProduct>().eq("id",2).like("name","小王").orderByDesc("age").ne("name","www"));
1
查询不为空的某字段 isNotNull
List<PmsProduct> list1 = pmsProductService.list(Wrappers.<PmsProduct>lambdaQuery().isNotNull(PmsProduct::getBrandName));
1
//分页page
 Page<PmsProduct> pmsProductPage = pmsProductService.page(new Page<PmsProduct>(1, 10), new QueryWrapper<>(new PmsProduct()));
1
//筛选对像的某一个具体属性 select
Integer countyId = sysAreaService.getObj(new QueryWrapper<SysArea>().select("id").eq("name", location.getCity()), o -> (Integer) o);
1
//在某个范围内 between
// 分页查询 10 条姓名为‘张三’、性别为男，且年龄在18至50之间的用户记录
List<User> userList = userMapper.selectPage(
        new Page<User>(1, 10),
        new EntityWrapper<User>().eq("name", "张三")
                .eq("sex", 0)
                .between("age", "18", "50")