前面一章Mybatis入門概述及第一個Mybatis實例實現增刪改查 ，已經搭建好了eclipse,mybatis,mysql的環境，並且實現了一個簡單的查詢。請注意，這種方式是用SqlSession實例來直接執行已映射的SQL語句：
session.selectOne("com.mucfc.model.EmployeerMapper.findEmployeerByID", 1);
其實還有更簡單的方法，而且是更好的方法，使用合理描述參數和SQL語句返回值的接口（比如EmployeerMapper.java），這樣現在就可以至此那個更簡單，更安全的代碼，沒有容易發生的字符串文字和轉換的錯誤.下面是詳細過程:
本文要改成以接口類來實現增刪改查
整個工程目錄 ：
本文示例工程免費下載
1、首先還是mybatis的配置文件mybatis-config.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">
<!-- 這是根標簽 -->
<configuration>
<!-- 元素允許在主配置文件之外提供一個properties格式對應文件，從而使得主配置文件更加通用。這樣對部署非常有用 -->
<properties resource="mysql.properties" />
<!-- 設置別名，一定要放在properties下面 -->
<typeAliases>
<typeAlias alias="Employeer" type="com.mucfc.model.Employeer" />
</typeAliases>
<!-- 配置數據源相關的信息 -->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<dataSource type="POOLED">
<!-- <property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/test?characterEncoding=UTF-8"/>
<property name="username" value="root"/>
<property name="password" value="christmas258@"/> -->
<property name="driver" value="${driver}" />
<property name="url" value="${url}" />
<property name="username" value="${username}" />
<property name="password" value="${password}" />
</dataSource>
</environment>
</environments>
<!-- 列出映射文件 -->
<mappers>
<mapper resource="com/mucfc/model/Employeer.xml" />
</mappers>
</configuration>
其中配置文件mysql.properties
driver=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/test?charset=utf8 username=root password=christmas258@
2、數據表對應的類Employeer.JAVA
package com.mucfc.model;
import java.io.Serializable;
/**
* 雇員信息類
*@author linbingwen
*@time 2015.5.11
*/
public class Employeer {
private Integer employeer_id;
private String employeer_name;
private Integer employeer_age ;
private String employeer_department;
private String employeer_worktype;
public Employeer() {
super();
}
public Integer getEmployeer_id() {
return employeer_id;
}
public void setEmployeer_id(Integer employeer_id) {
this.employeer_id = employeer_id;
}
public String getEmployeer_name() {
return employeer_name;
}
public void setEmployeer_name(String employeer_name) {
this.employeer_name = employeer_name;
}
public Integer getEmployeer_age() {
return employeer_age;
}
public void setEmployeer_age(Integer employeer_age) {
this.employeer_age = employeer_age;
}
public String getEmployeer_department() {
return employeer_department;
}
public void setEmployeer_department(String employeer_department) {
this.employeer_department = employeer_department;
}
public String getEmployeer_worktype() {
return employeer_worktype;
}
public void setEmployeer_worktype(String employeer_worktype) {
this.employeer_worktype = employeer_worktype;
}
@Override
public String toString() {
return "Employeer [employeer_id=" + employeer_id + ", employeer_name="
+ employeer_name + ", employeer_age=" + employeer_age
+ ", employeer_department=" + employeer_department
+ ", employeer_worktype=" + employeer_worktype + "]";
}
}
然後是SQL語句的配置Employeer.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="com.mucfc.mapper.EmployeerMapper">
<!-- 查找 -->
<select id="findEmployeerByID" parameterType="int" resultType="Employeer">
select* from `t_employeer` where employeer_id =#{employeer_id}
</select>
<!-- 插入 -->
<!-- useGeneratedKeys設置為"true"表明要MyBatis獲取由數據庫自動生成的主鍵；keyProperty="id"指定把獲取到的主鍵值注入到Employeer的id屬性 -->
<insert id="addEmployeer" parameterType="Employeer"
useGeneratedKeys="true" keyProperty="employeer_id">
insert into `t_employeer`(employeer_name,employeer_age,employeer_department,employeer_worktype)
values(#{employeer_name},#{employeer_age},#{employeer_department},#{employeer_worktype})
</insert>
<!-- 刪除 -->
<delete id="deleteEmployeer" parameterType="int">
delete from `t_employeer` where employeer_id = #{employeer_id}
</delete>
<!-- 修改 -->
<update id="updateEmployeer" parameterType="Employeer">
update t_employeer set employeer_name = #{employeer_name},employeer_age= #{employeer_age},employeer_department = #{employeer_department}
,employeer_worktype=#{employeer_worktype} where employeer_id = #{employeer_id}
</update>
</mapper>
4、SQL語句映射類EmployeerMapper.java
package com.mucfc.mapper;
import com.mucfc.model.Employeer;
/**
* SQL語句映射類
* @author linbingwen
* @time 2015.5.11
*/
public interface EmployeerMapper {
/**
* 注意要和Employeer.xml的方法名對應
*/
public Employeer findEmployeerByID(int id);
/**
* 注意要和Employeer.xml的方法名對應
*/
public void addEmployeer(Employeer employeer);
/**
* 注意要和Employeer.xml的方法名對應
*/
public void deleteEmployeer(int id);
/**
* 注意要和Employeer.xml的方法名對應
*/
public void updateEmployeer(Employeer employeer);
}
5、測試：
（1）增加命令
上一講Mybatis入門概述及第一個Mybatis實例實現增刪改查 中的方式：
/**
* 增加
*/
public static void addEmployeer(Employeer employeer){
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
//返回值是記錄條數
int resultCount = session.insert("com.mucfc.model.EmployeerMapper.addEmployeer", employeer );
System.out.printf("當前插入的employeer_id :%d 當前插入數據庫中條數:%d " , employeer.getEmployeer_id() ,resultCount); //獲取插入對象的id
System.out.println("");
session.commit() ;
} finally {
session.close();
}
}
/**
* 增加
*/
public static void addEmployeer(Employeer employeer){
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
employeerMapper.addEmployeer(employeer);
session.commit() ;
} finally {
session.close();
}
}
上一講【Mybatis】Mybatis入門概述及第一個Mybatis實例實現增刪改查 中的方式：
/**
* 刪除
*
*/
public static void deleteEmployeer(int id){
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
//返回值是記錄條數
int resultCount=session.delete("com.mucfc.model.EmployeerMapper.deleteEmployeer",id);
System.out.println("當前刪除數據庫中條數: "+resultCount); //獲取插入對象的id
session.commit() ;
} finally {
session.close();
}
}
改成以接口編程的方式：
/**
* 刪除
*
*/
public static void deleteEmployeer(int id){
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
employeerMapper.deleteEmployeer(id);
session.commit() ;
} finally {
session.close();
}
}
（3）查找命令
上一講【Mybatis】Mybatis入門概述及第一個Mybatis實例實現增刪改查 中的方式：
/**
* 查找
*/
public static void findEmployeerById(int id) {
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
Employeer employeer = (Employeer) session.selectOne(
"com.mucfc.model.EmployeerMapper.findEmployeerByID", 1);
if (employeer == null)
System.out.println("null");
else
System.out.println(employeer);
} finally {
session.close();
}
}
改成以接口編程的方式：
/**
* 查找
*/
public static void findEmployeerById(int id) {
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
Employeer employeer=employeerMapper.findEmployeerByID(id);
if (employeer == null)
System.out.println("null");
else
System.out.println(employeer);
} finally {
session.close();
}
}
（4）修改命令
上一講【Mybatis】Mybatis入門概述及第一個Mybatis實例實現增刪改查 中的方式：
/**
* 更改
*/
public static void updateEmployeer(Employeer employeer){
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
session.update("com.mucfc.model.EmployeerMapper.updateEmployeer",employeer);
session.commit() ;
} finally {
session.close();
}
}
改成以接口編程的方式：
/**
* 更改
*/
public static void updateEmployeer(Employeer employeer){
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
employeerMapper.updateEmployeer(employeer);
session.commit() ;
} finally {
session.close();
}
}
package com.mucfc.test;
import java.io.IOException;
import java.io.Reader;
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 com.mucfc.mapper.EmployeerMapper;
import com.mucfc.model.Employeer;
public class MybatisTest {
private static SqlSessionFactory sqlSessionFactory;
private static Reader reader;
static {
try {
reader = Resources.getResourceAsReader("mybatis-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 查找
*/
public static void findEmployeerById(int id) {
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
Employeer employeer=employeerMapper.findEmployeerByID(id);
if (employeer == null)
System.out.println("null");
else
System.out.println(employeer);
} finally {
session.close();
}
}
/**
* 增加
*/
public static void addEmployeer(Employeer employeer){
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
employeerMapper.addEmployeer(employeer);
session.commit() ;
} finally {
session.close();
}
}
/**
* 刪除
*
*/
public static void deleteEmployeer(int id){
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
employeerMapper.deleteEmployeer(id);
session.commit() ;
} finally {
session.close();
}
}
/**
* 更改
*/
public static void updateEmployeer(Employeer employeer){
SqlSession session = null;
try {
session = sqlSessionFactory.openSession();
EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
employeerMapper.updateEmployeer(employeer);
session.commit() ;
} finally {
session.close();
}
}
public static void main(String[] args) {
Employeer employeer1=new Employeer();
employeer1.setEmployeer_name("李四");
employeer1.setEmployeer_age(23);
employeer1.setEmployeer_department("產品一部");
employeer1.setEmployeer_worktype("開發工程師");
Employeer employeer2=new Employeer();
employeer2.setEmployeer_name("張三");
employeer2.setEmployeer_age(30);
employeer2.setEmployeer_department("產品二部");
employeer2.setEmployeer_worktype("測試工程師");
Employeer employeer3=new Employeer();
employeer3.setEmployeer_name("小王");
employeer3.setEmployeer_age(22);
employeer3.setEmployeer_department("產品三部");
employeer3.setEmployeer_worktype("數據分析師");
Employeer employeer4=new Employeer();
employeer4.setEmployeer_name("明明");
employeer4.setEmployeer_age(22);
employeer4.setEmployeer_department("財會部");
employeer4.setEmployeer_worktype("財務人員");
//插入
addEmployeer(employeer1);
addEmployeer(employeer2);
addEmployeer(employeer3);
addEmployeer(employeer4);
findEmployeerById(26);
deleteEmployeer(27);
//更改
employeer2.setEmployeer_id(28);
employeer2.setEmployeer_age(21);
employeer2.setEmployeer_department("產品四部");
updateEmployeer(employeer2);
}
}
插入了4條數據，ID為25~28
然後27號被刪除
29號被修改
