MyBatis--单表增删改查

冷不防 2021-08-13 23:32 449阅读 0赞

#### 准备表 ####

![在这里插入图片描述][20191025193248673.png]

#### 创建项目并导包 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70]

#### 创建User类 ####

package pers.zhang.po;
    
    import java.io.Serializable;
    import java.util.Date;
    
    public class User implements Serializable { 
    	/** * */
    	private static final long serialVersionUID = 1L;
    	private Integer id;
    	private String username;// 用户姓名
    	private String sex;// 性别
    	private Date birthday;// 生日
    	private String address;// 地址
    
    
    	public Integer getId() { 
    		return id;
    	}
    	public void setId(Integer id) { 
    		this.id = id;
    	}
    	public String getUsername() { 
    		return username;
    	}
    	public void setUsername(String username) { 
    		this.username = username;
    	}
    	public String getSex() { 
    		return sex;
    	}
    	public void setSex(String sex) { 
    		this.sex = sex;
    	}
    	public Date getBirthday() { 
    		return birthday;
    	}
    	public void setBirthday(Date birthday) { 
    		this.birthday = birthday;
    	}
    	public String getAddress() { 
    		return address;
    	}
    	public void setAddress(String address) { 
    		this.address = address;
    	}
    	@Override
    	public String toString() { 
    		return "User [id=" + id + ", username=" + username + ", sex=" + sex
    				+ ", birthday=" + birthday + ", address=" + address + "]";
    	}
    }

#### 书写配置文件 ####

log4j.properties:

# Global logging configuration
    log4j.rootLogger=ERROR,stdout
    # MyBatis logging configuration...
    log4j.logger.pers.zhang=DEBUG
    # Console output...
    log4j.appender.stdout=org.apache.log4j.ConsoleAppender
    log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
    log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

jdbc.properties:

jdbc.driver=com.mysql.jdbc.Driver
    jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8
    jdbc.username=root
    jdbc.password=123456

sqlMapCongfig.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>
    	<properties resource="jdbc.properties"/>
    	
    	<typeAliases>
    		<package name="pers.zhang.po"/>
    	</typeAliases>
    	
    	<environments default="development">
    		<environment id="development">
    			
    			<transactionManager type="JDBC" />
    			
    			<dataSource type="POOLED">
    				<property name="driver" value="${jdbc.driver}" />
    				<property name="url" value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8" />
    				<property name="username" value="root" />
    				<property name="password" value="123456" />
    			</dataSource>
    		</environment>
    	</environments>
    	
    	
    	<mappers>
    		<mapper resource="pers/zhang/mapper/UserMapper.xml" />
    	</mappers>
    </configuration>

#### 映射文件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="test">
    	
    	<select id="findUserById" parameterType="Integer" resultType="User">
    		select * from user where id = #{v}
    	</select>
    	
    	
    	<select id="findUserByUsername" parameterType="String" resultType="pers.zhang.po.User">
    		select * from user where username like "%"#{haha}"%"
    	</select>
    	
    	
    	<insert id="insertUser" parameterType="pers.zhang.po.User">
    		<selectKey keyProperty="id" resultType="Integer" order="AFTER">
    			select LAST_INSERT_ID()
    		</selectKey>
    		insert into user (username,birthday,address,sex) 
    		values (#{username},#{birthday},#{address},#{sex})
    	</insert>
    	
    	
    	<update id="updateUserById" parameterType="pers.zhang.po.User">
    		update user 
    		set username = #{username},sex = #{sex},birthday = #{birthday},address = #{address}
    		where id = #{id}
    	</update>
    	
    	
    	<delete id="deleteUserById" parameterType="Integer">
    		delete from user 
    		where id = #{vvvvv}
    	</delete>
    
    
    </mapper>

#### 查询 ####

@Test
    public void testMybatis() throws Exception { 
    	//加载核心配置文件
    	String resource = "sqlMapConfig.xml";
    	InputStream in = Resources.getResourceAsStream(resource);
    	//创建SqlSessionFactory
    	SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
    	//创建SqlSession
    	SqlSession sqlSession = sqlSessionFactory.openSession();
    	
    	//执行Sql语句 
    	User user = sqlSession.selectOne("findUserById", 1);
    	
    	System.out.println(user);
    }

控制台打印：

User [id=1, username=王五, sex=0, birthday=Fri Oct 25 00:00:00 CST 2019, address=北京]

#### 模糊查询 ####

@Test
    public void testfindUserByUsername() throws Exception { 
    	//加载核心配置文件
    	String resource = "sqlMapConfig.xml";
    	InputStream in = Resources.getResourceAsStream(resource);
    	//创建SqlSessionFactory
    	SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
    	//创建SqlSession
    	SqlSession sqlSession = sqlSessionFactory.openSession();
    	
    	//执行Sql语句 
    	List<User> users = sqlSession.selectList("findUserByUsername", "五");
    	for (User user2 : users) { 
    		System.out.println(user2);
    		
    	}
    }

控制台打印：

User [id=1, username=王五, sex=0, birthday=Fri Oct 25 00:00:00 CST 2019, address=北京]
    User [id=5, username=五菱宏光, sex=null, birthday=null, address=null]

#### insert操作 ####

@Test
    public void testInsertUser() throws Exception { 
    	//加载核心配置文件
    	String resource = "sqlMapConfig.xml";
    	InputStream in = Resources.getResourceAsStream(resource);
    	//创建SqlSessionFactory
    	SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
    	//创建SqlSession
    	SqlSession sqlSession = sqlSessionFactory.openSession();
    	
    	//执行Sql语句 
    	User user = new User();
    	user.setUsername("李雷");
    	user.setBirthday(new Date());
    	user.setAddress("北京");
    	user.setSex("男");
    	int i = sqlSession.insert("insertUser", user);
    	sqlSession.commit();
    	
    	System.out.println(user.getId());
    	
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70 1]

#### update操作 ####

@Test
    public void testUpdateUserById() throws Exception { 
    	//加载核心配置文件
    	String resource = "sqlMapConfig.xml";
    	InputStream in = Resources.getResourceAsStream(resource);
    	//创建SqlSessionFactory
    	SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
    	//创建SqlSession
    	SqlSession sqlSession = sqlSessionFactory.openSession();
    	
    	//执行Sql语句 
    	User user = new User();
    	user.setId(1);
    	user.setUsername("修改后的王五");
    	user.setBirthday(new Date());
    	user.setAddress("北京");
    	user.setSex("0");
    	int i = sqlSession.update("test.updateUserById", user);
    	sqlSession.commit();
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70 2]

#### delete操作 ####

@Test
    public void testDelete() throws Exception { 
    	//加载核心配置文件
    	String resource = "sqlMapConfig.xml";
    	InputStream in = Resources.getResourceAsStream(resource);
    	//创建SqlSessionFactory
    	SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
    	//创建SqlSession
    	SqlSession sqlSession = sqlSessionFactory.openSession();
    	
    	sqlSession.delete("test.deleteUserById", 1);
    	sqlSession.commit();
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70 3]

[20191025193248673.png]: /images/20210813/3ae22e3b1bdf49a0b4afb35d987020ed.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70]: /images/20210813/a1444c4ca5f745228d49f0238f07c208.png
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2NvbGRfX19wbGF5_size_16_color_FFFFFF_t_70 3]: /images/20210813/5caf497abc3549068287aa4d73c2c549.png