编写代码要实现的业务：
使用MyBatis框架完成：
增2.删3.改4.查的业务操作
文件目录：
bean包中填写的代码为实体类
dao模型就是写一个类，把访问数据库的代码封装起来
test是代码的测试类文件
lib包里面放的是myBatis框架.jar包
MYSQL代码部分
#判断存在即删除数据库
drop database if exists mydb;
#创建数据库
create database mydb;
#使用数据库
use mydb;
#创建数据表
create table emp(
eid int primary key AUTO_INCREMENT, #员工工号
ename varchar(20), #员工姓名
dept varchar(20), #员工部门
job varchar(20),#职位
sal double,#薪资
phone varchar(11),#电话
address varchar(100)#地址
);
#添加数据
insert into emp(ename,dept,job,sal,phone,address) values('张翠萍','测试部','测试工程
师',5800,'15821563548','郑州');
insert into emp(ename,dept,job,sal,phone,address) values('李耀菲','测试部','测试经
理',9800,'13658942168','许昌');
insert into emp(ename,dept,job,sal,phone,address) values('王长林','研发部','开发工程
师',8800,'13954865721','南阳');
insert into emp(ename,dept,job,sal,phone,address) values('陈清泰','研发部','开发经
理',14900,'13785463249','洛阳');
insert into emp(ename,dept,job,sal,phone,address) values('赵德保','运维部','运维工程
师',5200,'15785642139','信阳');
insert into emp(ename,dept,job,sal,phone,address) values('刘瑞琳','运维部','产品经
理',12600,'17956248563','商丘');
#查询所有数据
select * from emp;
1.bean包实体类文件
User：
package com.man.bean;
public class User {
private Integer uid;
private String username;
private String password;
private String phone;
private String address;
public Integer getUid() {
return uid;
}
public void setUid(Integer uid) {
this.uid = uid;
}
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 getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "User{" +
"uid=" + uid +
", username='" + username + '\'' +
", password='" + password + '\'' +
", phone='" + phone + '\'' +
", address='" + address + '\'' +
'}';
}
}
2.dao包访问数据库的代码
UserDao:
注意： 因为使用myBatis框架后我们不需要再写连接数据库的具体代码，只需要写一个接口类，编写需要执行操作的方法名称，参数和返回值
package com.man.dao;
import com.man.bean.User;
import java.util.List;
public interface UserDao {
List<User> selectAllUser();
User selectByUid(int uid);
int addUser(User user);
int delUser(int uid);
int updateUser(User user);
}
但是需要配置与UserDao相关联的UserDao.xml文件
在UserDao.xml中编写主要的sql代码
<?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">
<!--namespace是映射的dao接口-->
<mapper namespace="com.man.dao.UserDao">
<select id="selectAllUser" resultType="com.man.bean.User">
select *
from t_user;
</select>
<select id="selectByUid" parameterType="int" resultType="com.man.bean.User">
select *
from t_user
where uid = #{uid};
</select>
<insert id="addUser" parameterType="com.man.bean.User">
insert into t_user(username, password, phone, address)
values (#{username}, #{password}, #{phone}, #{address});
</insert>
<delete id="delUser" parameterType="int">
delete
from t_user
where uid = #{uid};
</delete>
<update id="updateUser" parameterType="com.man.bean.User">
update t_user
set username = #{username},
password = #{password},
phone = #{phone},
address = #{address}
where uid = #{uid};
</update>
</mapper>3.src文件夹下的核心文件
核心文件标准名称：SqlMapConfig.xml
注意：只能放在src文件夹下
<?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>
<!--配置mybatis连接的数据库的环境信息:使用default指定默认的连接环境-->
<environments default="mysql">
<environment id="mysql">
<!--配置事务处理的方式:默认使用JDBC的方式处理事务-->
<transactionManager type="jdbc"></transactionManager>
<!--配置数据源：默认使用连接池pooled-->
<dataSource type="pooled">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mydb"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
<environment id="oracle">
<transactionManager type=""></transactionManager>
<dataSource type=""></dataSource>
</environment>
</environments>
<mappers>
<mapper class="com.man.dao.UserDao"></mapper>
</mappers>
</configuration>
核心文件路径不能出现错误，长按Ctrl键鼠标放到UserDao上会跳转到指定文件路径的文件
