1. mybatis环境搭建与增删改查

开发环境

1. IDE: Eclipse

2. 数据库: Mysql 5.7

3. 数据库连接工具：DBeaver

步骤

1. 新建maven工程，命名为learnMybaits

2. 在pom.xml中引入mybatis、 mysql驱动和Junit的依赖

   pom.xml

   
       4.0.0
       com.auuid
       mybatis
       0.0.1-SNAPSHOT
   
       
           
           
               org.mybatis
               mybatis
               3.4.6
           
           
           
               mysql
               mysql-connector-java
               8.0.11
           
           
           
               junit
               junit
               4.11
               test
           
       
   
   

3. 新建一个Employee类，新建一张employee表

   Employee类

   package com.auuid.bean;
   
   public class Employee {
   
     private Integer id;
     private String name;
     private Integer age;
     
     public Integer getId() {
       return id;
     }
     public void setId(Integer id) {
       this.id = id;
     }
     public String getName() {
       return name;
     }
     public void setName(String name) {
       this.name = name;
     }
     public Integer getAge() {
       return age;
     }
     public void setAge(Integer age) {
       this.age = age;
     }
   }
   
   

   employee表

   CREATE TABLE employee (
     id INT PRIMARY KEY AUTO_INCREMENT,
     name VARCHAR(255),
     age SMALLINT
   )
   

4. 新建EmployeeMapper接口

   package com.auuid.dao;
   
   import com.auuid.bean.Employee;
   
   public interface EmployeeMapper {
     public Employee getById(Integer id);
     public void save(Employee employee);
     public void update(Employee employee);
     public void deleteById(Integer id);
   }
   

5. 新建配置文件EmployeeMapper.xml和mybatis-config.xml

   EmployeeMapper.xml

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

   mybatis-config.xml

6. 新建测试类EmployeeTestCase

   package com.auuid;
   
   import java.io.IOException;
   import java.io.InputStream;
   import java.util.Random;
   import java.util.UUID;
   
   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.auuid.bean.Employee;
   import com.auuid.dao.EmployeeMapper;
   
   public class EmployeeTestCase {
     
     @Test
     public void save() throws IOException {
       SqlSession openSession = null;
       
       try {
         openSession = openSession();
         EmployeeMapper employeeMapper = openSession.getMapper(EmployeeMapper.class); //生产接口代理对象
         employeeMapper.save(newEmployee());
         openSession.commit();
       } finally {
         openSession.close();
       }
     }
     
     private SqlSession openSession() throws IOException {
       InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml"); //读取数据源
       SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); //构建sessionFactory
       SqlSession openSession = sqlSessionFactory.openSession(); //构建session
       return openSession;
     }
     
     private Employee newEmployee() {
       Employee employee = new Employee();
       employee.setName(UUID.randomUUID().toString());
       employee.setAge(new Random().nextInt(100));
       return employee;
     }
   }