Mybatis CRUD 操作

梦里梦外; 2021-09-22 10:24 457阅读 0赞

**前置内容  =>  **[Mybatis查询数据库][Mybatis]

**项目结构：**

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userMapper.xml

<?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.cheese.mapping.userMapper">
        
        
        
        <select id="getUser" parameterType="int" resultType="com.cheese.pojo.User">
            select * from t_user where userid=#{userID}
        </select>
        
        
        <select id="getUserList" resultType="com.cheese.pojo.User">
            select * from t_user where userid <=3
        </select>
        
        <insert id="addUser" parameterType="map">
            insert into t_user(userid,username,password,name) 
              values(#{userID},#{userName},#{password},#{name})       
        </insert> 	
        
        <update id="updateUser" parameterType="map">
            update t_user set name=#{name},password=#{password} where userid=#{userID}
        </update>    
        
        <delete id="deleteUser" parameterType="map">
            delete from t_user where userid=#{userID}
        </delete>    
    </mapper>

User 实体类：

package com.cheese.pojo;
    
    public class User
    {
    	private int userID;
        private String userName;//用户名
        private String password;
        private String name;//全名
    
    	public User()
        {
        }
    
    	
        public int getUserID() {
    		return userID;
    	}
        
    	public void setUserID(int userID) {
    		this.userID = userID;
    	}
    
    	public String getUserName()
        {
            return userName;
        }
    
        public void setUserName(String userName)
        {
            this.userName = userName;
        }
    
        public String getPassword()
        {
            return password;
        }
    
        public void setPassword(String password)
        {
            this.password = password;
        }
        
        public String getName() {
    		return name;
    	}
    
    	public void setName(String name) {
    		this.name = name;
    	}   
    }

自定义Mybatis 工具类：

package com.cheese.test;
    
    import java.io.InputStream;
    
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    
    public class SessionUtil {
        private static final String resource = "config.xml";//mybatis配置文件        
        private static InputStream is;  
        private static SqlSessionFactory sessionFactory;	
    	static {
            is = SessionUtil.class.getClassLoader().getResourceAsStream(resource);//加载mybatis配置文件
            //创建sqlSession工厂
            sessionFactory = new SqlSessionFactoryBuilder().build(is);    		
    	}
    	
    	public static SqlSession getSession() {
            //创建sqlSession
            SqlSession session = sessionFactory.openSession();		
            return session;
    	}
    }

**测试程序：**

package com.cheese.test;
    
    import java.util.List;
    
    import org.apache.ibatis.session.SqlSession;
    
    import com.cheese.pojo.User;
    import org.junit.Test;
    public class TestCRUD{	
    
        @Test
        public void addUser(){
            SqlSession sqlSession = SessionUtil.getSession();
            /**
             * 映射sql的字符串，
             * com.cheese.mapping.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
             * addUser是insert标签的id属性值
             */
            String insertStr = "com.cheese.mapping.userMapper.addUser";//namespace + id 定位到要执行的sql语句
            User user = new User();
            user.setUserName("Jane");
            user.setPassword("a111");
            user.setName("Jane Austen");
            //插入
            int rowCount = sqlSession.insert(insertStr,user);
            sqlSession.commit();//提交事务
            sqlSession.close();//关闭session
            System.out.println("新增记录数：" + rowCount);
        }
        
        @Test
        public void getUserList(){
            SqlSession sqlSession = SessionUtil.getSession();
            String getListStr = "com.cheese.mapping.userMapper.getUserList";
            //执行查询操作，将查询结果自动封装成List<User>返回
            List<User> userList = sqlSession.selectList(getListStr);
            sqlSession.close();
            System.out.println(userList.get(1).getName());//打印第个User对象的name属性值
        }    
        
        @Test
        public void updateUser(){
            SqlSession sqlSession = SessionUtil.getSession();
            String updateStr = "com.cheese.mapping.userMapper.updateUser";
            User user = new User();
            user.setUserID(3);
            user.setName("匹特");
            user.setPassword("p111");
            //修改
            int rowCount = sqlSession.update(updateStr,user);
            sqlSession.commit();
            sqlSession.close();
            System.out.println("被修改记录数：" + rowCount);
        }
        
        @Test
        public void deleteUser(){
            SqlSession sqlSession = SessionUtil.getSession();
            String deleteStr = "com.cheese.mapping.userMapper.deleteUser";
            //删除
            int rowCount = sqlSession.delete(deleteStr,2);
            sqlSession.commit();
            sqlSession.close();
            System.out.println("被删除记录数：" + rowCount);
        }  
    }

Mybatis配置文件： 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>
        <environments default="development">
            <environment id="development">
                <transactionManager type="JDBC" />
                
                <dataSource type="POOLED">
                    <property name="driver" value="com.mysql.jdbc.Driver" />
                    <property name="url" value="jdbc:mysql://localhost:3306/base6"/>
                    <property name="username" value="btsuser" />
                    <property name="password" value="b111" />
                </dataSource>
            </environment>              
        </environments>
            
        <mappers>
            
            <mapper resource="com/cheese/mapping/userMapper.xml"/>
    
        </mappers>        
    </configuration>

**运行测试：**

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[Mybatis]: http://blog.csdn.net/write6/article/details/79214539
[SouthEast]: /images/20210920/66981760ee444d9886dd7df25057036b.png
[SouthEast 1]: /images/20210920/9c5e2b01e7394b6d9ce07f23f810279f.png
[SouthEast 2]: /images/20210920/5befd658ef7b47fdbed672f5e48009be.png
[SouthEast 3]: /images/20210920/8ca6be422eca4820ac922fbb53694ef3.png
[SouthEast 4]: /images/20210920/fe0014e77bad49239adaa3bf5fd9b736.png
[SouthEast 5]: /images/20210920/ba632bff571447d6ab5867a849a37acb.png