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文件结构

2.1基于XML的增、删、改、查

2.1.1定义sql映射文件

   
       
        
        
            select * from user where id=#{id}        
        
    
            insert into user(name,age) values(#{name},#{age})    
        
        
    
            delete from user where id=#{id}    
        
        
    
            update user set name=#{name},age=#{age} where id=#{id}    
        
        
            select * from user     
   

2.1.2在config.xml文件中注册这个映射文件

2.1.3定义一个MybatisUtil类，主要用于获取SqlSession

package com.util;import java.io.IOException;import java.io.Reader;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;public class MybatisUtil {    public static SqlSession getSession() throws IOException    {        String resource = "config.xml";        //加载 mybatis 的配置文件（它也加载关联的映射文件）        Reader reader = Resources.getResourceAsReader(resource);        //构建 sqlSession 的工厂        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);        //openSession的参数设置为true表示自动提交        SqlSession session=sessionFactory.openSession(true);        return session;    }}

2.1.4定义相应的测试方法

package com.test;import java.io.IOException;import java.io.Reader;import java.util.List;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import org.junit.Test;import com.entity.User;import com.util.MybatisUtil;public class Test1 {
       @Test    public void getUser() throws IOException    {        String resource = "config.xml";        //加载 mybatis 的配置文件（它也加载关联的映射文件）        Reader reader = Resources.getResourceAsReader(resource);        //构建 sqlSession 的工厂        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);        //创建能执行映射文件中 sql 的 sqlSession        SqlSession session = sessionFactory.openSession();        //映射 sql 的标识字符串        String statement = "com.config.userMapper.getUser";        //执行查询返回一个唯一 user 对象的 sql        User user = session.selectOne(statement, 15);        session.close();        System.out.println(user);    }    //测试插入    @Test    public void addUser() throws IOException    {        SqlSession session=MybatisUtil.getSession();        String statement="com.config.userMapper.addUser";        //insert表示有几天记录发生了变化        int insert=session.insert(statement, new User(-1,"王五",29));        session.close();        System.out.println(insert);    }    //测试删除    @Test    public void deleteUser() throws IOException    {        SqlSession session=MybatisUtil.getSession();        String statement="com.config.userMapper.deleteUser";        int delete=session.delete(statement, 15);        session.close();        System.out.println(delete);    }    //测试更新    @Test    public void updateUser() throws IOException    {        SqlSession session=MybatisUtil.getSession();        String statement="com.config.userMapper.updateUser";        int update=session.update(statement, new User(16,"马六",34));        session.close();        System.out.println(update);    }    //测试获得整个表    @Test    public void getAllUsers() throws IOException    {        SqlSession session=MybatisUtil.getSession();        String statement="com.config.userMapper.getAllUsers";        List
   
     list=session.selectList(statement);        for(User user:list)        {            System.out.println(user);        }        session.close();    }}
   

2.2基于注解的增、删、改、查

2.2.1定义sql映射接口

package com.inter;import java.util.List;import org.apache.ibatis.annotations.Delete;import org.apache.ibatis.annotations.Insert;import org.apache.ibatis.annotations.Select;import org.apache.ibatis.annotations.Update;import com.entity.User;public interface UserMapper {
       @Insert("insert into user(name,age) values(#{name},#{age})")    public int add(User user);    @Delete("delete from user where id=#{id}")    public int deleteById(int id);    @Update("update user set name=#{name},age=#{age} where id=#{id}")    public int update(User user);    @Select("select * from user where id=#{id}")    public User getById(int id);    @Select("select * from user")    public List
   
     getAll();}
   

2.2.2在config.xml中注册这个映射接口

2.2.3编写测试方法

package com.test;import java.io.IOException;import java.util.List;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.junit.Test;import com.entity.User;import com.inter.UserMapper;import com.util.MybatisUtil;public class Test2 {    //测试添加    @Test    public void testAdd() throws IOException    {        SqlSession session=MybatisUtil.getSession();        UserMapper mapper=session.getMapper(UserMapper.class);        int add=mapper.add(new User(-1,"王五",12));        session.close();        System.out.println(add);    }    //测试删除    @Test    public void testDelete() throws IOException    {        SqlSession session=MybatisUtil.getSession();        UserMapper mapper=session.getMapper(UserMapper.class);        int delete=mapper.deleteById(17);        session.close();        System.out.println(delete);    }    //测试更新    @Test    public void testUpdate() throws IOException    {        SqlSession session=MybatisUtil.getSession();        UserMapper mapper=session.getMapper(UserMapper.class);        int update=mapper.update(new User(16,"王五",17));        session.close();        System.out.println(update);    }    //测试查询    @Test    public void testGetUsers() throws IOException    {        SqlSession session=MybatisUtil.getSession();        UserMapper mapper=session.getMapper(UserMapper.class);        List
   
     list=mapper.getAll();        for(User user:list)        {            System.out.println(user);        }        session.close();    }}
   

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