集成 Mybatis

1.添加依赖

pom 依赖

<!-- MySQL -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

<!-- MyBatis -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
</dependency>

2.添加配置

yml:

# MyBatis
mybatis:
  mapper-locations: classpath:/mapper/*Mapper.xml
  type-aliases-package: com.qyfl.weichat.pojo

# MyBatis 日志
logging:
  level:
    com.qyfl.wechat.dao: debug

SpringBootApplication:

@SpringBootApplication
@MapperScan("com.qyfl.wechat.dao")
public class WechatApplication {

    public static void main(String[] args) {
        SpringApplication.run(WechatApplication.class, args);
    }

}

3. 数据库中的表映射出来的对象（POJO）

@Data
@NoArgsConstructor
@AllArgsConstructor
public class ProductCategory {

    private Integer categoryId;

    private String categoryName;

    private Integer categoryType;

    private Date createTime;

    private Date updateTime;
}

4. DAO

@Repository
public interface ProductCategoryMapper {
    ProductCategory selectByPrimaryKey(Integer categoryId);

    int insert(ProductCategory productCategory);
}

5. xml

然后就可以在 resources/mapper（这个路径在 yml 中的 mapper-locations 里配置） 下新建 xml 文件了。

resultMap 里的配置要与数据库对应起来。

<?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.qyfl.wechat.dao.ProductCategoryMapper">
    <resultMap id="BaseResultMap" type="com.qyfl.wechat.pojo.ProductCategory">
        <constructor>
            <idArg column="category_id" jdbcType="INTEGER" javaType="java.lang.Integer"/>
            <arg column="category_name" jdbcType="VARCHAR" javaType="java.lang.String"/>
            <arg column="category_type" jdbcType="INTEGER" javaType="java.lang.Integer"/>
            <arg column="create_time" jdbcType="TIMESTAMP" javaType="java.util.Date"/>
            <arg column="update_time" jdbcType="TIMESTAMP" javaType="java.util.Date"/>
        </constructor>
    </resultMap>

    <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">
        select * from product_category where category_id = #{categoryId,jdbcType=INTEGER}
    </select>

    <insert id="insert" parameterType="com.qyfl.wechat.pojo.ProductCategory">
        insert into product_category(category_id,category_name,category_type,create_time,update_time)
        value(#{categoryId,jdbcType=INTEGER}, #{categoryName,jdbcType=VARCHAR}, #{categoryType,jdbcType=INTEGER},  now(), now())
    </insert>

</mapper>

然后就可以在 service 中调用了。
下例是在 SpringBootTest 中测试用例：

@RunWith(SpringRunner.class)
@SpringBootTest
public class ProductCategoryMapperTest {

    @Autowired
    private ProductCategoryMapper productCategoryMapper;

    @Test
    @Transactional
    public void selectByPrimaryKeyTest() {
        ProductCategory category = productCategoryMapper.selectByPrimaryKey(1);
        System.out.println(category.toString());
    }

    @Test
    @Transactional
    public void insertTest() {
        ProductCategory category = new ProductCategory();
        category.setCategoryName("女生最爱");
        category.setCategoryType(2);

        Integer result = productCategoryMapper.insert(category);
        System.out.println(result);
    }
}