标签：status String companyName brand sqlSession brandName MyBatis

环境准备

• 导入POM依赖

  
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    
    <dependencies>
        <!--mybatis 依赖-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.5</version>
        </dependency>
    
        <!--mysql 驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.46</version>
        </dependency>
    
        <!--junit 单元测试-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>
    
        <!-- 添加slf4j日志api -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.20</version>
        </dependency>
        <!-- 添加logback-classic依赖 -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>
        <!-- 添加logback-core依赖 -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
            <version>1.2.3</version>
        </dependency>
    
    </dependencies>
  

• logback.xml

  <?xml version="1.0" encoding="UTF-8"?>
  <configuration>
      <appender name="Console" class="ch.qos.logback.core.ConsoleAppender">
          <encoder>
              <pattern>[%level]  %cyan([%thread]) %boldGreen(%logger{15}) - %msg %n</pattern>
          </encoder>
      </appender>
  
      <logger name="com.itheima" level="DEBUG" additivity="false">
          <appender-ref ref="Console"/>
      </logger>
  
      <root level="DEBUG">
          <appender-ref ref="Console"/>
      </root>
  </configuration>
  

• mybatis-config.xml

  <?xml version="1.0" encoding="UTF-8" ?>
  <!DOCTYPE configuration
          PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
          "http://mybatis.org/dtd/mybatis-3-config.dtd">
  <configuration>
  
      <typeAliases>
          <package name="cn.lixuan.pojo"/>
      </typeAliases>
      
      <!--
      environments：配置数据库连接环境信息。可以配置多个environment，通过default属性切换不同的environment
      -->
      <environments default="development">
          <environment id="development">
              <transactionManager type="JDBC"/>
              <dataSource type="POOLED">
                  <!--数据库连接信息-->
                  <property name="driver" value="com.mysql.jdbc.Driver"/>
                  <property name="url" value="jdbc:mysql:///mybatis?useSSL=false&amp;serverTimezone=Asia/Shanghai"/>
                  <property name="username" value="root"/>
                  <property name="password" value="root"/>
              </dataSource>
          </environment>
  
          <environment id="test">
              <transactionManager type="JDBC"/>
              <dataSource type="POOLED">
                  <!--数据库连接信息-->
                  <property name="driver" value="com.mysql.jdbc.Driver"/>
                  <property name="url" value="jdbc:mysql:///mybatis?useSSL=false"/>
                  <property name="username" value="root"/>
                  <property name="password" value="root"/>
              </dataSource>
          </environment>
      </environments>
      <mappers>
          <!--加载sql映射文件-->
         <!-- <mapper resource="cn/lixuan/mapper/UserMapper.xml"/>-->
  
          <!--Mapper代理方式-->
          <package name="cn.lixuan.mapper"/>
      </mappers>
  
  </configuration>
  

• 建表(tb_brand)

  -- 删除tb_brand表
  drop table if exists tb_brand;
  -- 创建tb_brand表
  create table tb_brand
  (
      -- id 主键
      id           int primary key auto_increment,
      -- 品牌名称
      brand_name   varchar(20),
      -- 企业名称
      company_name varchar(20),
      -- 排序字段
      ordered      int,
      -- 描述信息
      description  varchar(100),
      -- 状态：0：禁用  1：启用
      status       int
  );
  -- 添加数据
  insert into tb_brand (brand_name, company_name, ordered, description, status)
  values ('三只松鼠', '三只松鼠股份有限公司', 5, '好吃不上火', 0),
         ('华为', '华为技术有限公司', 100, '华为致力于把数字世界带入每个人、每个家庭、每个组织，构建万物互联的智能世界', 1),
         ('小米', '小米科技有限公司', 50, 'are you ok', 1);
  

• 编写实体类(cn.lixuan.brand.pojo.Brand)

  // 这里用Lombok自动生成Getter、Setter方法
  @Getter
  @Setter
  @ToString
  public class Brand {
      // id 主键
      private Integer id;
      // 品牌名称
      private String brandName;
      // 企业名称
      private String companyName;
      // 排序字段
      private Integer ordered;
      // 描述信息
      private String description;
      // 状态：0：禁用  1：启用
      private Integer status;
  }
  

• 编写测试用例(cn.lixuan.test.MybatisTest)

查询所有数据

• 编写接口方法(cn.lixuan.mapper.BrandMapper)

  public interface BrandMapper {
  
      /**
       * 查询所有
       */
      List<Brand> selectAll();
  }
  

• 编写SQL语句(BrandMapper.xml)

  <!-- 在 reources 下创建 cn/lixuan/mapper 目录结构，并在该目录下创建名为 BrandMapper.xml 的映射配置文件 -->
  
  <?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="cn.lixuan.mapper.BrandMapper">
      <select id="selectAll" resultType="brand">
          select *
          from tb_brand;
      </select>
  </mapper>
  

• 使用resultMap解决SQL表字段和实体类名称不一致问题

  <resultMap id="brandResultMap" type="brand">
      <result column="brand_name" property="brandName"/>
      <result column="company_name" property="companyName"/>
  </resultMap>
  
  <select id="selectAll" resultMap="brandResultMap">
      select *
      from tb_brand;
  </select>
  

• 编写测试方法(MybatisTest)

  @Test
  public void testSelectAll() throws IOException {
      //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();
  
      //3. 获取Mapper接口的代理对象
      BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
  
      //4. 执行方法
      List<Brand> brands = brandMapper.selectAll();
      System.out.println(brands);
  
      //5. 释放资源
      sqlSession.close();
  }
  

查询详情

• 编写接口方法

  /**
    * 查看详情：根据Id查询
    */
  Brand selectById(int id);
  

• 编写SQL语句

  <select id="selectById"  resultMap="brandResultMap">
      select *
      from tb_brand where id = #{id};
  </select>
  

• SQL语句中特殊字段处理

  • 使用转义字符
  • 使用CDATA区包裹

• 编写测试方法

   @Test
  public void testSelectById() throws IOException {
      //接收参数，该id以后需要传递过来
      int id = 1;
  
      //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();
  
      //3. 获取Mapper接口的代理对象
      BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
  
      //4. 执行方法
      Brand brand = brandMapper.selectById(id);
      System.out.println(brand);
  
      //5. 释放资源
      sqlSession.close();
  }
  

多条件查询

• 编写接口方法

  // 1
  List<Brand> selectByCondition(@Param("status") int status, @Param("companyName") String companyName,@Param("brandName") String brandName);
  
  // 2
  List<Brand> selectByCondition(Brand brand);
  
  // 3
  List<Brand> selectByCondition(Map map);
  

• 编写SQL语句

  <select id="selectByCondition" resultMap="brandResultMap">
      select *
      from tb_brand
      where status = #{status}
      and company_name like #{companyName}
      and brand_name like #{brandName}
  </select>
  

• 编写测试方法

  @Test
  public void testSelectByCondition() throws IOException {
      //接收参数
      int status = 1;
      String companyName = "华为";
      String brandName = "华为";
  
      // 处理参数
      companyName = "%" + companyName + "%";
      brandName = "%" + brandName + "%";
  
      //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();
      //3. 获取Mapper接口的代理对象
      BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
  
      //4. 执行方法
  	//方式一 ：接口方法参数使用 @Param 方式调用的方法
      //List<Brand> brands = brandMapper.selectByCondition(status, companyName, brandName);
      
      //方式二 ：接口方法参数是 实体类对象 方式调用的方法
       //封装对象
      /* Brand brand = new Brand();
          brand.setStatus(status);
          brand.setCompanyName(companyName);
          brand.setBrandName(brandName);*/
      
      //List<Brand> brands = brandMapper.selectByCondition(brand);
      
      //方式三 ：接口方法参数是 map集合对象 方式调用的方法
      Map map = new HashMap();
      map.put("status" , status);
      map.put("companyName", companyName);
      map.put("brandName" , brandName);
      List<Brand> brands = brandMapper.selectByCondition(map);
      System.out.println(brands);
  
      //5. 释放资源
      sqlSession.close();
  }
  

动态SQL

• 多条件 if, where

  <select id="selectByCondition" resultMap="brandResultMap">
      select *
      from tb_brand
      <where>
          <if test="status != null">
              and status = #{status}
          </if>
          <if test="companyName != null and companyName != '' ">
              and company_name like #{companyName}
          </if>
          <if test="brandName != null and brandName != '' ">
              and brand_name like #{brandName}
          </if>
      </where>
  </select>
  

• 单条件 choose,when

  <select id="selectByConditionSingle" resultMap="brandResultMap">
      select *
      from tb_brand
      <where>
          <choose><!--相当于switch-->
              <when test="status != null"><!--相当于case-->
                  status = #{status}
              </when>
              <when test="companyName != null and companyName != '' "><!--相当于case-->
                  company_name like #{companyName}
              </when>
              <when test="brandName != null and brandName != ''"><!--相当于case-->
                  brand_name like #{brandName}
              </when>
          </choose>
      </where>
  </select>
  

• 编写测试方法

  @Test
  public void testSelectByConditionSingle() throws IOException {
      //接收参数
      int status = 1;
      String companyName = "华为";
      String brandName = "华为";
  
      // 处理参数
      companyName = "%" + companyName + "%";
      brandName = "%" + brandName + "%";
  
      //封装对象
      Brand brand = new Brand();
      //brand.setStatus(status);
      brand.setCompanyName(companyName);
      //brand.setBrandName(brandName);
  
      //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();
      //3. 获取Mapper接口的代理对象
      BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);
      //4. 执行方法
      List<Brand> brands = brandMapper.selectByConditionSingle(brand);
      System.out.println(brands);
  
      //5. 释放资源
      sqlSession.close();
  }
  

添加数据

• 编写接口方法

   /**
     * 添加
     */
  void add(Brand brand);
  

• 编写SQL语句

  <!-- useGeneratedKeys="true" keyProperty="id" 添加成功后返回主键 -->
  <insert id="add" useGeneratedKeys="true" keyProperty="id">
      insert into tb_brand (brand_name, company_name, ordered, description, status)
      values (#{brandName}, #{companyName}, #{ordered}, #{description}, #{status});
  </insert>
  

• 编写测试方法

  @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); //设置自动提交事务，这种情况不需要手动提交事务了
      //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();
  }
  

修改

• 编写接口类

   /**
     * 修改
     */
  void update(Brand brand);
  

• 编写SQL语句

  <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>
  

• 编写测试方法

  @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";
      int ordered = 200;
      int id = 6;
  
      //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();
  }
  

删除一行数据

• 编写接口方法

  /**
    * 根据id删除
    */
  void deleteById(int id);
  

• 编写SQL语句

  <delete id="deleteById">
      delete from tb_brand where id = #{id};
  </delete>
  

• 编写测试方法

   @Test
  public void testDeleteById() throws IOException {
      //接收参数
      int id = 6;
  
      //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();
  }
  

批量删除

• 编写接口方法

  /**
    * 批量删除
    */
  void deleteByIds(int[] ids);
  

• 编写SQL语句

  <delete id="deleteByIds">
      delete from tb_brand where id
      in
      <foreach collection="array" item="id" separator="," open="(" close=")">
          #{id}
      </foreach>
      ;
  </delete>
  

• 编写测试方法

  @Test
  public void testDeleteByIds() throws IOException {
      //接收参数
      int[] ids = {5,7,8};
  
      //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();
  }
  

注解实现CRUD

• 查询 ：@Select
• 添加 ：@Insert
• 修改 ：@Update
• 删除 ：@Delete

标签：status,String,companyName,brand,sqlSession,brandName,MyBatis
来源： https://www.cnblogs.com/19BigData/p/16643095.html

本站声明： 1. iCode9 技术分享网（下文简称本站）提供的所有内容，仅供技术学习、探讨和分享；
2. 关于本站的所有留言、评论、转载及引用，纯属内容发起人的个人观点，与本站观点和立场无关；
3. 关于本站的所有言论和文字，纯属内容发起人的个人观点，与本站观点和立场无关；
4. 本站文章均是网友提供，不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属；如您发现该文章侵犯了您的权益，可联系我们第一时间进行删除；
5. 本站为非盈利性的个人网站，所有内容不会用来进行牟利，也不会利用任何形式的广告来间接获益，纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。