list查询

1、项目结构

 

2、EmployeeMapper.xml添加代码

<!-- public List<Employee> getEmpsByListNameLike() ; 
              注意：返回值是集合类型，resultType中要写集合中元素类型
      -->
      <select id="getEmpsByListNameLike" resultType="com.atguigu.mybatis.bean.Employee">
          select * from tbl_employee where last_name like #{lastName}
      
      </select>

 注意：返回值是集合类型，resultType中要写集合中元素类型

3、mybatis-config.xml代码

<?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>

    <settings>  
               <!-- mybatis开启驼峰命名    lastName====>last_name -->
             <setting name="mapUnderscoreToCamelCase" value="true" />  
    </settings>  

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <!-- 配置数据库连接信息 -->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis" />
                <property name="username" value="root" />
                <property name="password" value="111111" />
            </dataSource>
        </environment>
    </environments>
    
       <mappers>
           <!-- 注册userMapper.xml文件， 
            resoure:引用类路径下的sql映射文件 
                    mybatis/mapper/EmployeeMapper.xml
            url:引用网络路径或磁盘下的sql映射文件
                    file:///var/mappers/AuthorMapper.xml
            class：引用注册接口
                ①、有sql配置文件：映射文件名必须和接口同名，并且放在与接口同一目录下
                ②、没有sql映射文件：所有的sql都是利用注解写在接口上
                ③、推荐：比较重要的，复杂的Dao接口，写sql映射文件，便于维护
                            不重要，简单的Dao接口为了开发快速可以写注解
            package：用于有sql映射文件的接口注册
                    <package name="com.atguigu.mybatis.dao"/>
        -->
        <mapper resource="com/atguigu/mybatis/dao/EmployeeMapper.xml"/>
        <mapper class="com.atguigu.mybatis.dao.EmployeeMapperAnnotation"/>
           <!-- <package name="com.atguigu.mybatis.dao"/> -->
       </mappers> 
   
</configuration>

注：①configuration中标签顺序：properties, settings, typeAliases, typeHandlers, objectFactory, objectWrapperFactory, reflectorFactory?, plugins, environments, databaseIdProvider, mappers

　　  ②mybatis开启驼峰命名 lastName====>last_name

　　　　<settings>  
             <setting name="mapUnderscoreToCamelCase" value="true" />  
    　　</settings> 

　　　　　　

4、MybatisTest.java代码

@Test
    public void test05() throws IOException {
        SqlSessionFactory sqlSessionFactory =getSqlSessionFactory();
        //1、获取到的SqlSession不会自动提交
        SqlSession openSession= sqlSessionFactory.openSession();
        try {
            /*2.获取接口的实现对象*/
            EmployeeMapper mapper= openSession.getMapper(EmployeeMapper.class);
            //mapper为代理对象，执行增删改查
            
            List<Employee> list=mapper.getEmpsByListNameLike("%e%");
            for (Employee employee : list) {
                System.out.println(employee);
            }
            //3、手动提交
            openSession.commit();
            
        } finally {
            openSession.close();
        }
    }

5、控制台打印