mybatis-plus整合springboot入门
1、mybatis-plus快速入门
2、springboot整合mybatis-plus
（1）、映入maven依赖
<!--mybaitsi-plus-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.3.1.tmp</version>
</dependency>备注：springboot版本：2.2.6.RELEASE
（2）、yml文件数据库和mybatis-plus配置
#数据库配置
spring:
datasource:
username: root
password: 123456
url: jdbc:mysql://localhost:3306/mybaits-plus?useUnicode=true&characterEncoding=UTF-8&useSSL=false&nullCatalogMeansCurrent=true&serverTimezone=Asia/Shanghai
#mybatis-plus配置
logging:
level:
com:
example:
demo:
mapper: debug
mybatis-plus:
mapper-locations: classpath*:mappers/*.xml
# 实体扫描，多个package用逗号或者分号分隔
type-aliases-package: com.example.demo.model
configuration:
# 驼峰下划线转换
map-underscore-to-camel-case: true
cache-enabled: false
call-setters-on-nulls: true
global-config:
# 刷新mapper 调试神器
refresh: true
banner: false
#数据库大写下划线转换
#capital-mode: true
#序列接口实现类配置
#key-generator: com.baomidou.springboot.xxx
# 数据库相关配置
db-config:
db-type: mysql
# 主键类型 AUTO:"数据库ID自增", INPUT:"用户输入ID",ID_WORKER:"全局唯一ID (数字类型唯一ID)", UUID:"全局唯一ID UUID";
id-type: AUTO
# 字段策略 IGNORED:"忽略判断",NOT_NULL:"非 NULL 判断"),NOT_EMPTY:"非空判断"
field-strategy: not_empty
capital-mode: true
#逻辑删除配置
logic-delete-value: 1
logic-not-delete-value: 0（3）、数据准备
CREATE TABLE `user` ( `id` bigint(11) NOT NULL COMMENT ‘主键ID‘, `name` varchar(30) NOT NULL COMMENT ‘姓名‘, `age` int(11) NOT NULL COMMENT ‘年龄‘, `email` varchar(50) NOT NULL COMMENT ‘邮箱‘, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; INSERT INTO `mybaits-plus`.`user` (`id`, `name`, `age`, `email`) VALUES (‘1‘, ‘Jone‘, ‘18‘, ‘‘); INSERT INTO `mybaits-plus`.`user` (`id`, `name`, `age`, `email`) VALUES (‘2‘, ‘Jack‘, ‘20‘, ‘‘); INSERT INTO `mybaits-plus`.`user` (`id`, `name`, `age`, `email`) VALUES (‘3‘, ‘Tom‘, ‘28‘, ‘‘); INSERT INTO `mybaits-plus`.`user` (`id`, `name`, `age`, `email`) VALUES (‘4‘, ‘Sandy‘, ‘21‘, ‘‘); INSERT INTO `mybaits-plus`.`user` (`id`, `name`, `age`, `email`) VALUES (‘5‘, ‘Billie‘, ‘24‘, ‘‘); CREATE TABLE `course` ( `id` bigint(20) NOT NULL, `course` varchar(10) NOT NULL, `user_id` bigint(20) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; INSERT INTO `mybaits-plus`.`course` (`id`, `course`, `user_id`) VALUES (‘1‘, ‘语文‘, ‘2‘);
（4）、创建实体类
@Data
public class User implements Serializable {
private static final long serialVersionUID = -5817579076869802231L;
private Long id;
private String name;
private Integer age;
private String email;
}（5）、service层和dao层
public interface UserService extends IService<User> {
PageInfo<User> selectPage(int pageNo, int pageSize, User user);
PageInfo<User> selectPageCustom(int pageNo, int pageSize, User user);
PageInfo<Map<String, Object>> selectPageCustomMap(int pageNo, int pageSize);
}@Service
public class UserServiceImpl extends ServiceImpl<UserMapper,User> implements UserService {
@Resource
private UserMapper userMapper;
@Override
public PageInfo<User> selectPage(int pageNo, int pageSize, User user) {
Page<User> page = new Page<>(pageNo,pageSize,false);
QueryWrapper<User> wrapper = new QueryWrapper<>();
wrapper.like("name",user.getName());
wrapper.orderByAsc("id");
page = userMapper.selectPage(page, wrapper);
return new PageInfo<>(page);
}
@Override
public PageInfo<User> selectPageCustom(int pageNo, int pageSize, User user) {
Page<User> page = new Page<>(pageNo,pageSize);
userMapper.pageMyQuery(page,user.getName());
return new PageInfo<>(page);
}
@Override
public PageInfo<Map<String, Object>> selectPageCustomMap(int pageNo, int pageSize) {
Page<Map<String, Object>> page = new Page<>(pageNo,pageSize);
page = userMapper.pageMyMapQuery(page);
return new PageInfo<>(page);
}public interface UserMapper extends BaseMapper<User> {
Page<User> pageMyQuery(Page<User> pageInfo, @Param("name") String name);
Page<Map<String,Object>> pageMyMapQuery(Page pageInfo);
}mapper文件
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mapper.UserMapper">
<select id="pageMyQuery" parameterType="User" resultType="User">
select id,name,age from user where name = #{name}
</select>
<select id="pageMyMapQuery" resultType="map">
SELECT * FROM course c
LEFT JOIN `user` u on c.id = u.id
</select>
</mapper>（6）、单元测试
@SpringBootTest
@RunWith(SpringRunner.class)
public class MybatisPlusTest {
@Autowired
private UserService userService;
/**
* 全局id生成器
*/
@Autowired
private DefaultIdentifierGenerator defaultIdentifierGenerator;
/**
* list查询
*/
@Test
public void selectList(){
List<User> list = userService.list();
Assert.assertEquals(6, list.size());
list.forEach(System.out::println);
}
/**
*单条插入
*/
@Test
public void inset(){
User user = new User();
user.setName("张三");
user.setAge(20);
user.setEmail("");
user.setId(defaultIdentifierGenerator.nextId(user));
userService.save(user);
}
/**
* 批量插入
*/
@Test
public void saveBatch(){
List<User> list = new ArrayList<>();
User user1 = new User();
user1.setName("王五");
user1.setAge(20);
user1.setEmail("");
user1.setId(defaultIdentifierGenerator.nextId(user1));
list.add(user1);
User user2 = new User();
user2.setName("李四");
user2.setAge(20);
user2.setEmail("");
user2.setId(defaultIdentifierGenerator.nextId(user1));
list.add(user2);
userService.saveBatch(list);
}
/**
* 按照id集合删除
*/
@Test
public void delBatch(){
List<Long> ids = new ArrayList<>();
ids.add(1259742998092120066L);
ids.add(1259749231041806337L);
userService.removeByIds(ids);
}
/**
* 分页查询
*/
@Test
public void queryPage(){
User user = new User();
user.setName("李四");
PageInfo<User> userPageInfo = userService.selectPage(1,3,user);
System.err.println(userPageInfo);
}
/**
* 自定义分页查询返回T
*/
@Test
public void queryPageCustom(){
User user = new User();
user.setName("李四");
PageInfo<User> userPageInfo = userService.selectPageCustom(1,3,user);
System.err.println(userPageInfo);
}
/**
* 自定义分页查询返回map
*/
@Test
public void queryPageCustomMap(){
PageInfo<Map<String,Object>> userPageInfo = userService.selectPageCustomMap(1,3);
System.err.println(userPageInfo);
}补充：PageInfo源码（自定义分页实体类）
@Datapublic class PageInfo<T> { /** * 当前页 */ private Long pageNo; /** * 每页显示条数 */ private Long PageSize; /** * 总条数 */ private Long total; /** * 结果集 */ private List<T> result; public PageInfo(Page<T> page) { this.pageNo = page.getCurrent(); this.PageSize = page.getSize(); this.total = page.getTotal(); this.result = page.getRecords(); }}
mybatis-plus配置类
@Configurationpublic class MybatisPlusConfig { /** * 全局id生成器 * @return */ @Bean public DefaultIdentifierGenerator identifierGenerator(){ return new DefaultIdentifierGenerator(); } /** * 分页插件 * @return */ @Bean public PaginationInterceptor paginationInterceptor(){ PaginationInterceptor paginationInterceptor = new PaginationInterceptor(); // 设置请求的页面大于最大页后操作， true调回到首页，false 继续请求 默认false // paginationInterceptor.setOverflow(false); // 设置最大单页限制数量，默认 500 条，-1 不受限制 // paginationInterceptor.setLimit(500); // 开启 count 的 join 优化,只针对部分 left join paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true)); return paginationInterceptor; }}