Spring Boot整合MyBatis

基础环境搭建:

搭建步骤:

  1. 数据准备:创建数据库、数据表并插入一定的数据。
  2. 创建项目,引入相应的启动器:使用Spring Initializr的方式构建项目,选择MySQL和MyBatis依赖,编写实体类。
  3. 编写配置文件:在配置文件中进行数据库连接配置以及进行第三方数据源的默认参数覆盖。
  • 创建数据库:
CREATE DATABASE springbootdata;
CREATE TABLE t_article (
  id int(20) NOT NULL AUTO_INCREMENT COMMENT '文章id',
  title varchar(200) NULL COMMENT '文章标题',
  content longtext COMDEFAULTMENT '文章内容',
  PRIMARY KEY (id)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
INSERT INTO t_article VALUES ('1', 'Spring Boot基础入门', '从入门到精通讲解...');
INSERT INTO t_article VALUES ('2', 'Spring Cloud基础入门', '从入门到精通讲解...');
CREATE TABLE t_comment (
  id int(20) NOT NULL AUTO_INCREMENT COMMENT '评论id',
  content longtext COMMENT '评论内容',
  author varchar(200) DEFAULT NULL COMMENT '评论作者',
  a_id int(20) DEFAULT NULL COMMENT '关联的文章id',
  PRIMARY KEY (id)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
INSERT INTO t_comment VALUES ('1', '很全、很详细', '狂奔的蜗牛', '1');
INSERT INTO t_comment VALUES ('2', '赞一个', 'tom', '1');
INSERT INTO t_comment VALUES ('3', '很详细', 'kitty', '1');
INSERT INTO t_comment VALUES ('4', '很好,非常详细', '张三', '1');
INSERT INTO t_comment VALUES ('5', '很不错', '张杨', '2');
  • 引入依赖(pom.xml):
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.0.0</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.10</version>
</dependency>
  • 创建实体类:
public class Comment {
    private Integer id;
    private String content;
    private String author;
    private Integer aId;
}
  • 编写配置文件(application.properties):
spring.datasource.url=jdbc:mysql://localhost:3306/springbootdata?serverTimezone=UTC
spring.datasource.username=用户名
spring.datasource.password=密码
spring.datasource.type = com.alibaba.druid.pool.DruidDataSource
spring.datasource.initialSize=20
spring.datasource.minIdle=10
spring.datasource.maxActive=100

使用注解方式整合MyBatis:

整合步骤:

  1. 创建Mapper接口文件:@Mapper

    @Mapper
    public interface CommentMapper {
        //查询数据操作
        @Select("SELECT * FROM t_comment WHERE id =#{id}")
        public Comment findById(Integer id);
        //插入数据操作
        @Insert("INSERT INTO t_comment(content,author,a_id) " +
                "values (#{content},#{author},#{aId})")
        public int insertComment(Comment comment);
        //更新数据操作
        @Update("UPDATE t_comment SET content=#{content} WHERE id=#{id}")
        public int updateComment(Comment comment);
        //删除数据操作
        @Delete("DELETE FROM t_comment WHERE id=#{id}")
        public int deleteComment(Integer id);}
    }
    

     

  2. 编写测试方法进行接口方法测试及整合测试

    @RunWith(SpringRunner.class)
    @SpringBootTest
    public class MyBatisDemoApplicationTests {
        @Autowired
        private CommentMapper commentMapper;
        @Test
        public void selectComment() {
            Comment comment = commentMapper.findById(1);
            System.out.println(comment);
        }
    }
    

使用配置文件整合MyBatis:

整合步骤:

  1. 创建Mapper接口文件:@Mapper

    @Mapper
    public interface ArticleMapper {
        public Article selectArticle(Integer id);
        public int updateArticle(Article article);
    }
    
  2. 创建XML映射文件:编写对应的SQL语句

    <?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.xiaodaidai.mapper.ArticleMapper">
        <resultMap id="articleWithComment" type="Article">
            <id property="id" column="id" />
            <result property="title" column="title" />
            <result property="content" column="content" />
            <collection property="commentList" ofType="Comment">
                <id property="id" column="c_id" />
                <result property="content" column="c_content" />
                <result property="author" column="author" />
            </collection>
        </resultMap>
        <select id="selectArticle" resultMap="articleWithComment">
           SELECT a.*,c.id c_id,c.content c_content,c.author
           FROM t_article a,t_comment c
           WHERE a.id=c.a_id AND a.id = #{id}
        </select>
        <update id="updateArticle" parameterType="Article" >
            UPDATE t_article
            <set>
                <if test="title !=null and title !=''">
                    title=#{title},
                </if>
                <if test="content !=null and content !=''">
                    content=#{content}
                </if>
            </set>
            WHERE id=#{id}
        </update>
    </mapper>
    

     

  3. 在全局文件(application.properties)中配置XML映射文件路径以及实体类别名映射路径

    #配置MyBatis的xml配置文件路径
    mybatis.mapper-locations=classpath:mapper/*.xml
    #配置XML映射文件中指定的实体类别名路径
    mybatis.type-aliases-package=com.xiaodaidai.domain
    
  4. 编写测试方法进行接口方法测试及整合测试

    @Autowired
    private ArticleMapper articleMapper;
    @Test
    public void selectArticle() {
        Article article = articleMapper.selectArticle(1);
        System.out.println(article);
    }
    
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