创建数据库（y2165）

MyBatis环境搭建

1.在pom.xml引入依赖

2.得替换build节点，为了让程序编译在main中所有子包下的配置文件

3.构建大配置，位于resources

<?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">

<!-- 通过这个配置文件,完成mybatis与数据库的连接 -->

<configuration><!--根节点-->

<!--别名设定-->

<typeAliases>

<package name="cn.happy.entity"/>

</typeAliases>

<environments default="development">

<environment id="development">

<!--

transactionManager:JDBC保证事务的

update

delete

事务分类：JDBC:编程式事务

xxx.beginTransaction()

tx.commit()

tx.rollback()

配置式事务

JDBC|MANAGED

区别

-->

<!-- 配置事物管理采用JDBC -->

<transactionManager type="JDBC"/>

<!--

POOLED：MyBatis内置的连接池

c3p0连接池

POOLED 、UNPOOLED 、JNDI

-->

<!-- POOLED:mybatis的数据源,JNDI:基于tomcat的数据源 -->

<dataSource type="POOLED">

<property name="driver" value="com.mysql.jdbc.Driver"/>

<property name="url" value="jdbc:mysql:///y2165"/>

<property name="username" value="cd"/>

<property name="password" value="000"/>

</dataSource>

</environment>

</environments>

<mappers>

<mapper resource="cn/happy/dao/IDeptDAO.xml"/>

</mappers>

</configuration>

4.构建实体类

package cn.happy.entity;

/**

* Created by lenovo on 2017/7/7.

*/

public class Dept {

private Integer deptNo;

private String deptName;

public Integer getDeptNo() {

return deptNo;

}

public void setDeptNo(Integer deptNo) {

this.deptNo = deptNo;

}

public String getDeptName() {

return deptName;

}

public void setDeptName(String deptName) {

this.deptName = deptName;

}

}

5.构建小配置

<?xml version="1.0" encoding="UTF-8" ?>

<!--头文件-->

<!DOCTYPE mapper

PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"

"http://mybatis.org/dtd/mybatis-3-mapper.dtd ">

<!--namespace：

命名空间：区分不同空间下的同名SQLID

A： findlAll

B: findAll

-->

<mapper namespace="cn.happy.dao.IDeptDAO" >

<!--SQL标签

id:唯一锁定到SQL标识

paramenterType:SQL语句的入参 可以省略

resultType：

增删除操作：不能 写

查询：单个实体的类型

-->

<!--查询所有-->

<select id="getAllList" resultType="Dept">

SELECT * FROM Dept

</select>

<!--待条件查询-->

<select id="getDeptById" parameterType="int" resultType="Dept">

select * from Dept where deptNo=#{deptNo}

</select>

</mapper>

6.在大配置中关联小配置

<mappers>

<mapper resource="cn/happy/dao/IDeptDAO.xml"/>

</mappers>

7.书写测试类

package cn.happy.test;

import cn.happy.dao.IDeptDAO;

import cn.happy.entity.Dept;

import org.apache.ibatis.io.Resources;

import org.apache.ibatis.jdbc.SQL;

import org.apache.ibatis.session.SqlSession;

import org.apache.ibatis.session.SqlSessionFactory;

import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import org.junit.Test;

import java.io.IOException;

import java.io.InputStream;

import java.util.List;

/**

* Created by lenovo on 2017/7/9.

*/

public class MyBatisTest01 {

//单元测试

@Test

//1.查询所有使用getMapper()

public void testall() {

//1 获取到大配置

String path = "mybatis-config.xml";

try {

InputStream is = Resources.getResourceAsStream(path);

SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);

SqlSession session = factory.openSession();

IDeptDAO de = session.getMapper(IDeptDAO.class);

List<Dept> list = de.getAllList();

for (Dept dept : list) {

System.out.println(dept.getDeptName());

}

} catch (IOException e) {

e.printStackTrace();

}

}

@Test

//2.待条件查询 Mapper的使用

public void testGetOneDept() {

String path = "mybatis-config.xml";

try {

InputStream is = Resources.getResourceAsStream(path);

SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);

SqlSession session = factory.openSession();

IDeptDAO dao = session.getMapper(IDeptDAO.class);

Dept dept = dao.getDeptById(1);

System.out.println(dept.getDeptName());

} catch (IOException e) {

e.printStackTrace();

}

}

使用getMapper查询所有结果

使用getMapper带条件查询结果