查询专栏：建议使用LambdaQueryWrapper，防误写

/*** 这样写的好处防误写*/@Testpublic void selectLambda() {
//    LambdaQueryWrapper<User> lambda = new QueryWrapper<User>().lambda();
//    LambdaQueryWrapper<User> lambdaQueryWrapper = new LambdaQueryWrapper<>();LambdaQueryWrapper<User> lambdaQuery = Wrappers.<User>lambdaQuery();lambdaQuery.like(User::getName, "雨").lt(User::getAge, 40);List<Object> userList = userMapper.selectObjs(lambdaQuery);userList.forEach(System.out::println);}/*** 5. 名字为王姓并且(年龄小于40或者邮箱不为空)* sql：name like '王%' and (age < 40 or email is not null)*/@Testpublic void selectLambda2() {LambdaQueryWrapper<User> lambdaQuery = Wrappers.<User>lambdaQuery();lambdaQuery.likeRight(User::getName, "雨").lt(User::getAge, 40).isNotNull(User::getEmail);List<Object> userList = userMapper.selectObjs(lambdaQuery);userList.forEach(System.out::println);}@Testpublic void selectLambda3() {List<User> userList = new LambdaQueryChainWrapper<User>(userMapper).like(User::getName, "雨").ge(User::getAge, 20).list();userList.forEach(System.out::println);}

想学习更多微服务、分布式、中间件、数据库、项目快速构建等系列技术
请访问https://gblfy.com
让我们一起进步！！！