第一个Mybatis程序

文章中的jar包和约束文件在主页

导入jar包：

sqlMapConfig.xml文件

Mapper.xml文件

配置mybatis约束

点Window->Preferences 搜索XML Catalog点添加Location为文件地址

mybatis-3-config.dtd文件对应的key为：-//mybatis.org//DTD Config 3.0//EN
mybatis-3-mapper.dtd文件对应的key为：-//mybatis.org//DTD Mapper 3.0//EN

包装类User：

public class User {
   
   private Integer u_id;
   private String u_username;
   private String u_password;
   private String u_sex;
   private Date u_createTime;
   private Integer u_cid;
   
   public User() {
   	super();
   	// TODO Auto-generated constructor stub
   }
   public User(Integer u_id, String u_username, String u_password, String u_sex, Date u_createTime, Integer u_cid) {
   	super();
   	this.u_id = u_id;
   	this.u_username = u_username;
   	this.u_password = u_password;
   	this.u_sex = u_sex;
   	this.u_createTime = u_createTime;
   	this.u_cid = u_cid;
   }
   public Integer getU_id() {
   	return u_id;
   }
   public void setU_id(Integer u_id) {
   	this.u_id = u_id;
   }
   public String getU_username() {
   	return u_username;
   }
   public void setU_username(String u_username) {
   	this.u_username = u_username;
   }
   public String getU_password() {
   	return u_password;
   }
   public void setU_password(String u_password) {
   	this.u_password = u_password;
   }
   public String getU_sex() {
   	return u_sex;
   }
   public void setU_sex(String u_sex) {
   	this.u_sex = u_sex;
   }
   public Date getU_createTime() {
   	return u_createTime;
   }
   public void setU_createTime(Date u_createTime) {
   	this.u_createTime = u_createTime;
   }
   public Integer getU_cid() {
   	return u_cid;
   }
   public void setU_cid(Integer u_cid) {
   	this.u_cid = u_cid;
   }
   @Override
   public String toString() {
   	return "User [u_id=" + u_id + ", u_username=" + u_username + ", u_password=" + u_password + ", u_sex=" + u_sex
   			+ ", u_createTime=" + u_createTime + ", u_cid=" + u_cid + "]";
   }
   
}

测试类：
Mapper.xml中的查询语句

select * from user where u_id=#{id}

查询语句

@Test
	public void test01() throws Exception {
		String resource="sqlMapConfig.xml";
		//读取配置文件
		InputStream inputStream=Resources.getResourceAsStream(resource);
		//需要SqlSessionFactoryBuilder
		SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
		//创建SqlSessionFactory
		SqlSessionFactory build = builder.build(inputStream);
		//生产一个SqlSession
		SqlSession openSession = build.openSession();
		//操作数据库
		//参数1：需要操作的sql语句 参数2：sql语句的参数
		//参数1中前部分为mapper.xml中mapper标签的namespace，后部分为对应语句的id
		User user = openSession.selectOne("userMapper.selectById", 1);
		System.out.println(user);
	}

后面的就与上面类似，只需要改对应的语句即可

插入语句

类中的参数名} 可调用类中对应的参数 -->

insert into user values(13,#{u_username},#{u_password},#{u_sex},#{u_createTime},#{u_cid})

User user=new User();
		user.setU_username("小明");
		user.setU_createTime(new Date());
		user.setU_cid(1);
		user.setU_password("12345");
		user.setU_sex("男");
		//参数1：需要操作的sql语句 参数2：sql语句的参数
		//参数1中前部分为mapper.xml中mapper标签的namespace，后部分为对应语句的id
		openSession.insert("userMapper.userInsert", user);
		//因为mysql中的事务默认需要主动提交所以调用commit()方法否则将会代码运行成功而数据库数据未被修改
		openSession.commit();

修改语句

update user set u_username=#{u_username} where u_id=#{u_id}

        User user=new User();
        user.setU_id(15);
		user.setU_username("小刚");
		//参数1：需要操作的sql语句 参数2：sql语句的参数
		//参数1中前部分为mapper.xml中mapper标签的namespace，后部分为对应语句的id
		openSession.update("userMapper.updateUser",user);
		openSession.commit();

删除语句

delete from user where u_id=#{id}

//参数1：需要操作的sql语句 参数2：sql语句的参数
		//参数1中前部分为mapper.xml中mapper标签的namespace，后部分为对应语句的id
openSession.delete("userMapper.deleteUser", 15);
		openSession.commit();