/**
* 要求:查询id=1的数据
*/
@Test
public void testFindOne() {
//方法一
User user = userMapper.selectById(1);
System.out.println(user);
//方法二
QueryWrapper<User> queryWrapper =
new QueryWrapper<>();
queryWrapper.eq("id", 1);
User user2 = userMapper.selectOne(queryWrapper);
System.out.println(user2);
}
/**
* 要求:查询age>1 and age<150 的数据
* 参数说明: > gt < lt = eq
* >=ge <= le
*/
@Test
public void testFindByAge() {
//方法二
QueryWrapper<User> queryWrapper =
new QueryWrapper<>();
queryWrapper.gt("age", 1)
.lt("age",150);
List<User> userList = userMapper.selectList(queryWrapper);
System.out.println(userList);
QueryWrapper<User> queryWrapper2 =
new QueryWrapper<>();
queryWrapper2.between("age", 1, 150);
List<User> userList2 = userMapper.selectList(queryWrapper2);
System.out.println(userList);
}
/**
* 3. 模糊查询 like %xxxx%
* 查询名称 %精%
*/
@Test
public void testFindByLike() {
QueryWrapper<User> queryWrapper = new QueryWrapper<User>();
queryWrapper.like("name", "精");
List<User> userList = userMapper.selectList(queryWrapper);
System.out.println(userList);
}
/**
* 4. 查询age=18岁 或者 女神仙 age>=300 sex=女
*
*/
@Test
public void testFindByWhere() {
QueryWrapper<User> queryWrapper = new QueryWrapper<User>();
queryWrapper.eq("age", 18)
.or()
.ge("age", 300)
.eq("sex", "女");
List<User> userList = userMapper.selectList(queryWrapper);
System.out.println(userList);
}
@Test
public void insert() {
User user = new User();
user.setId(null)
.setName("苍老师")
.setAge(30)
.setSex("女");
userMapper.insert(user);
}
/**
* 1.将苍老师名称改为林志玲
* 2.年龄改为18
* sql:update user set name=xxx,age=xxx
* where name=苍老师
*
* 修改参数说明:
* 1.entity 代表需要修改后的数据
* 2.updateWrapper 修改的条件构造器
*/
@Test
public void update() {
User user = new User();
user.setName("林志玲")
.setAge(18);
UpdateWrapper<User> updateWrapper =
new UpdateWrapper<>();
updateWrapper.eq("name", "苍老师");
userMapper.update(user, updateWrapper);
}