8.添加（增）
- 操作步骤
- 编写接口方法：Mapper接口
/** * 添加 */ void add(Brand brand);
- 编写SQL语句：SQL映射文件
<insert id="add"> insert into tb_brand (brand_name, company_name, ordered, description, status) values (#{brandName}, #{companyName}, #{ordered}, #{description}, #{status}); </insert>
- 编写测试样例
（默认需要手动提交事务： sqlSession.commit();）
@Test public void testAdd() throws IOException { //接收参数 int status = 1; String companyName = "波导手机"; String brandName = "波导"; String description = "手机中的战斗机"; int ordered = 100; //封装对象 Brand brand = new Brand(); brand.setStatus(status); brand.setCompanyName(companyName); brand.setBrandName(brandName); brand.setDescription(description); brand.setOrdered(ordered); //1. 获取SqlSessionFactory String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); //2. 获取SqlSession对象 SqlSession sqlSession = sqlSessionFactory.openSession(); //SqlSession sqlSession = sqlSessionFactory.openSession(true); //3. 获取Mapper接口的代理对象 BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class); //4. 执行方法 brandMapper.add(brand); //提交事务 sqlSession.commit(); //5. 释放资源 sqlSession.close(); }
- 运行结果
- 添加–主键返回
（无法通过brand对象直接获取id值）
- 获取brand对象的id
9.修改–改所有参数
- 操作步骤
- 编写接口方法：Mapper接口
/** * 修改 */ int update(Brand brand);
- 编写SQL语句：SQL映射文件
<update id="update"> update tb_brand set brand_name = #{brandName}, company_name = #{companyName}, ordered = #{ordered}, description = #{description}, status = #{status} where id = #{id}; </update>
- 编写测试样例
@Test public void testUpdate() throws IOException { //接收参数 int status = 0; String companyName = "波导手机"; String brandName = "波导"; String description = "波导手机,手机中的战斗机666"; int ordered = 200; int id = 4; //封装对象 Brand brand = new Brand(); brand.setStatus(status); brand.setCompanyName(companyName); brand.setBrandName(brandName); brand.setDescription(description); brand.setOrdered(ordered); brand.setId(id); //1. 获取SqlSessionFactory String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); //2. 获取SqlSession对象 SqlSession sqlSession = sqlSessionFactory.openSession(); //SqlSession sqlSession = sqlSessionFactory.openSession(true); //3. 获取Mapper接口的代理对象 BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class); //4. 执行方法 int count = brandMapper.update(brand); System.out.println(count); //提交事务 sqlSession.commit(); //5. 释放资源 sqlSession.close(); }
- 运行结果
10.修改–动态修改
- 操作步骤
（在修改的代码基础的基础上编码）
如果只传了密码，其他值不传,执行完其他值会变成null，这时需要动态字段解决该类问题
- 编写SQL语句：SQL映射文件
<update id="update"> update tb_brand <set> <if test="brandName != null and brandName != ''"> brand_name = #{brandName}, </if> <if test="companyName != null and companyName != ''"> company_name = #{companyName}, </if> <if test="ordered != null"> ordered = #{ordered}, </if> <if test="description != null and description != ''"> description = #{description}, </if> <if test="status != null"> status = #{status} </if> </set> where id = #{id}; </update>
- 编写测试样例
- 运行结果
11.删除–删除单条记录
- 操作步骤
- 编写接口方法：Mapper接口
/** * 根据id删除 */ void deleteById(int id);
- 编写SQL语句：SQL映射文件
<delete id="deleteById"> delete from tb_brand where id = #{id}; </delete>
- 编写测试样例
@Test public void testDeleteByIds() throws IOException { //接收参数 int id = 4; //1. 获取SqlSessionFactory String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); //2. 获取SqlSession对象 SqlSession sqlSession = sqlSessionFactory.openSession(); //SqlSession sqlSession = sqlSessionFactory.openSession(true); //3. 获取Mapper接口的代理对象 BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class); //4. 执行方法 brandMapper.deleteById(id); //提交事务 sqlSession.commit(); //5. 释放资源 sqlSession.close(); }
- 运行结果
12.删除–删除多条记录
- 操作步骤
2. 编写接口方法：Mapper接口
/** * 批量删除 */ void deleteByIds(int[] ids);
- 编写SQL语句：SQL映射文件
<!-- mybatis会将数组参数，封装为一个Map集合。 * 默认：array = 数组 * 使用@Param注解改变map集合的默认key的名称 --> <delete id="deleteByIds"> delete from tb_brand where id in <foreach collection="array" item="id" separator="," open="(" close=")"> #{id} </foreach> ; </delete>
- 编写测试样例
@Test public void testDeleteByIds() throws IOException { //接收参数 int[] ids = {1,2}; //1. 获取SqlSessionFactory String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); //2. 获取SqlSession对象 SqlSession sqlSession = sqlSessionFactory.openSession(); //SqlSession sqlSession = sqlSessionFactory.openSession(true); //3. 获取Mapper接口的代理对象 BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class); //4. 执行方法 brandMapper.deleteByIds(ids); //提交事务 sqlSession.commit(); //5. 释放资源 sqlSession.close(); }
- 运行结果
13.mybatis注解开发
`博客内容借鉴了bilibili黑马程序员SSM课程资料，如有侵权，请联系作者删除`
总结
欢迎各位留言交流以及批评指正，如果文章对您有帮助或者觉得作者写的还不错可以点一下关注,点赞，收藏支持一下。
