Mybatis Plus快速开始

此文章借鉴MyBatis官网，使用gradle构建项目，使用oracle数据库

本文代码地址见github仓库

NOTES：

Mybatis Plus使用

在测试这个案例时碰到一个坑，就是数据库表名 与 核心表名重复的时候，查询会报错 找不到表名。此处修改user表为users表了

1. 在build.gradle文件中配置依赖

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation group: 'com.baomidou', name: 'mybatis-plus-boot-starter', version: '3.2.0'
    compileOnly 'org.projectlombok:lombok'
    runtimeOnly 'com.oracle.database.jdbc:ojdbc8'
    annotationProcessor 'org.projectlombok:lombok'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

2. 配置 application.yml

spring:
  datasource:
    url: jdbc:oracle:thin:@192.168.3.161:1521:jc
    username: jc
    password: 123456
    driver-class-name: oracle.jdbc.driver.OracleDriver
    maximum-pool-size: 30

3. 编写实体类

@Data
public class Users {
    private Long id;
    private String name;
    private Integer age;
    private String email;
}

4. 编写Mapper类

@Mapper
public interface UserMapper extends BaseMapper<Users> {
}

5. 编写测试类

@SpringBootTest(classes = App.class)
public class SampleTest {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void testSelect() {
        System.out.println(("----- selectAll method test ------"));
        List<Users> userList = userMapper.selectList(null);
        Assert.isTrue(userList.size()==5, "结果集不为5条");
        userList.forEach(System.out::println);
    }
}

项目结构：

MyBatisPlus 字段类型处理器

字段类型处理器

usersMapper.selectOne(new QueryWrapper<JwtUserPO>().lambda().apply("USERNAME = {0,jdbcType=CHAR,typeHandler=" + TrimmedStringTypeHandler.class.getCanonicalName() + "}", username));