mybatis-plus快速入门相关代码

package com.mybatisplus; import com.baomidou.mybatisplus.extension.plugins.pagination.Page; import com.mybatisplus.mapper.UserMapper; import com.mybatisplus.pojo.User; import org.junit.jupiter.api.Test; import org.springframework.boot.test.context.SpringBootTest; import javax.annotation.Resource; import java.util.Arrays; import java.util.HashMap; import java.util.List; @SpringBootTest class MybatisPlusApplicationTests { //继承自BaseMapper，所有方法都来自父类，也可以编写自己的扩展方法 @Resource private UserMapper userMapper; //快速使用 @Test void contextLoads() { //通过id查询用户 // System.out.println(userMapper.selectById(4L)); //查询全部用户，其参数是一个条件构造器 userMapper.selectList(null).forEach(System.out::println); } //测试插入数据 @Test void testInsert() { User user = new User() .setName("小黎") .setAge(72) .setEmail("1933@qq.com"); userMapper.insert(user); } //测试更新数据 @Test void testUpdate() { User user = new User() .setId(1698244309027500042L) .setName("王五") .setAge(8) .setEmail("456@gmail.com"); int update = userMapper.updateById(user); System.out.println(update); } //测试乐观锁成功案例 @Test void testOptimisticLockSuccess() { //查询用户信息 User user = userMapper.selectById(1L); //修改用户信息 user.setAge(34).setName("丙丁"); userMapper.updateById(user); } //测试乐观锁失败案例 @Test void testOptimisticLockFail() { //线程1 User user = userMapper.selectById(1L); user.setAge(34).setName("丙丁11111"); //模拟另外一个线程执行插队操作 User user2 = userMapper.selectById(1L); user2.setAge(34).setName("丙丁22222"); userMapper.updateById(user2); //自旋锁多次提交 userMapper.updateById(user);//如果没有乐观锁，就会覆盖插队线程的值 } //测试通过id查询 @Test void testSelectById() { User user = userMapper.selectById(1L); System.out.println(user); } //批量查询多个用户 @Test void testSelectBatch() { List<User> users = userMapper.selectBatchIds(Arrays.asList(1L, 2L, 3L)); users.forEach(System.out::println); } //条件查询map @Test void testSelectByMaps() { HashMap<String, Object> map = new HashMap<>(); map.put("name", "丙丁22222"); map.put("age", 28); List<User> users = userMapper.selectByMap(map); users.forEach(System.out::println); } //测试分页查询 @Test void testPage() { //第一个参数：当前页 //第二个参数：页面的大小 Page<User> page = new Page<>(2, 3); Page<User> userPage = userMapper.selectPage(page, null); userPage.getRecords().forEach(System.out::println); } //测试删除 @Test void testDelete() { userMapper.deleteById(1698244309027500042L); } //测试批量删除 @Test void testDeleteBatch() { userMapper.deleteBatchIds(Arrays.asList(1L, 2L, 3L)); } //测试条件删除 @Test void testDeleteByMap() { HashMap<String, Object> map = new HashMap<>(); map.put("name", "小王"); userMapper.deleteByMap(map); //再查询逻辑删除的数据 userMapper.selectByMap(map).forEach(System.out::println); } @Test void testLogicDelete() { HashMap<String, Object> map = new HashMap<>(); map.put("name", "小王"); userMapper.deleteByMap(map); //再查询逻辑删除的数据 userMapper.selectByMap(map).forEach(System.out::println); } }