Mybatis接口编程方式实现增删改查
林炳文Evankaka原创作品。转自https://blog.csdn.net/Evankaka/article/details/45670527
前面一章【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 ，已经搭建好了eclipse,mybatis,mysql的环境，并且实现了一个简单的查询。请注意，这种方式是用SqlSession实例来直接执行已映射的SQL语句：
session.selectOne("com.mucfc.model.EmployeerMapper.findEmployeerByID", 1);
其实还有更简单的方法，而且是更好的方法，使用合理描述参数和SQL语句返回值的接口（比如EmployeerMapper.java），这样现在就可以至此那个更简单，更安全的代码，没有容易发生的字符串文字和转换的错误.下面是详细过程:
本文要改成以接口类来实现增删改查
整个工程目录 ：
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1、首先还是mybatis的配置文件mybatis-config.xml
-
xml version="1.0" encoding="UTF-8" ?>
-
-
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
-
"http://mybatis.org/dtd/mybatis-3-config.dtd">
-
-
<configuration>
-
-
<properties resource="mysql.properties" />
-
-
<typeAliases>
-
<typeAlias alias="Employeer" type="com.mucfc.model.Employeer" />
-
typeAliases>
-
-
<environments default="development">
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<environment id="development">
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<transactionManager type="JDBC" />
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<dataSource type="POOLED">
-
-
<property name="driver" value="${driver}" />
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<property name="url" value="${url}" />
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<property name="username" value="${username}" />
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<property name="password" value="${password}" />
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dataSource>
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environment>
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environments>
-
-
<mappers>
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<mapper resource="com/mucfc/model/Employeer.xml" />
-
mappers>
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configuration>
其中配置文件mysql.properties
2、数据表对应的类Employeer.JAVA
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package com.mucfc.model;
-
-
import java.io.Serializable;
-
-
/**
-
* 雇员信息类
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*@author linbingwen
-
*@time 2015.5.11
-
*/
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public
class Employeer {
-
private Integer employeer_id;
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private String employeer_name;
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private Integer employeer_age ;
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private String employeer_department;
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private String employeer_worktype;
-
-
public Employeer() {
-
super();
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}
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public Integer getEmployeer_id() {
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return employeer_id;
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}
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public void setEmployeer_id(Integer employeer_id) {
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this.employeer_id = employeer_id;
-
}
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public String getEmployeer_name() {
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return employeer_name;
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}
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public void setEmployeer_name(String employeer_name) {
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this.employeer_name = employeer_name;
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}
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public Integer getEmployeer_age() {
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return employeer_age;
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}
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public void setEmployeer_age(Integer employeer_age) {
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this.employeer_age = employeer_age;
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}
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public String getEmployeer_department() {
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return employeer_department;
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}
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public void setEmployeer_department(String employeer_department) {
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this.employeer_department = employeer_department;
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}
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public String getEmployeer_worktype() {
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return employeer_worktype;
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}
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public void setEmployeer_worktype(String employeer_worktype) {
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this.employeer_worktype = employeer_worktype;
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}
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@Override
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public String toString() {
-
return
"Employeer [employeer_id=" + employeer_id +
", employeer_name="
-
+ employeer_name +
", employeer_age=" + employeer_age
-
+
", employeer_department=" + employeer_department
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+
", employeer_worktype=" + employeer_worktype +
"]";
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}
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-
-
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}
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xml version="1.0" encoding="UTF-8" ?>
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"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
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<mapper namespace="com.mucfc.mapper.EmployeerMapper">
-
-
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<select id="findEmployeerByID" parameterType="int" resultType="Employeer">
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select* from `t_employeer` where employeer_id =#{employeer_id}
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select>
-
-
-
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<insert id="addEmployeer" parameterType="Employeer"
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useGeneratedKeys=
"true"
keyProperty=
"employeer_id">
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insert into `t_employeer`(employeer_name,employeer_age,employeer_department,employeer_worktype)
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values(#{employeer_name},#{employeer_age},#{employeer_department},#{employeer_worktype})
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insert>
-
-
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<delete id="deleteEmployeer" parameterType="int">
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delete from `t_employeer` where employeer_id = #{employeer_id}
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delete>
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-
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<update id="updateEmployeer" parameterType="Employeer">
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update t_employeer set employeer_name = #{employeer_name},employeer_age= #{employeer_age},employeer_department = #{employeer_department}
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,employeer_worktype=#{employeer_worktype} where employeer_id = #{employeer_id}
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update>
-
-
mapper>
注意com.mucfc.mapper.EmployeerMapper这个类是存在的，它是一个接口类，上一讲我们是使用 com.mucfc.model.EmployeerMapper，而上一讲的这个类是不存在的
4、SQL语句映射类EmployeerMapper.java
-
package com.mucfc.mapper;
-
-
import com.mucfc.model.Employeer;
-
-
/**
-
* SQL语句映射类
-
* @author linbingwen
-
* @time 2015.5.11
-
*/
-
public
interface EmployeerMapper {
-
/**
-
* 注意要和Employeer.xml的方法名对应
-
*/
-
public Employeer findEmployeerByID(int id);
-
-
/**
-
* 注意要和Employeer.xml的方法名对应
-
*/
-
public void addEmployeer(Employeer employeer);
-
-
/**
-
* 注意要和Employeer.xml的方法名对应
-
*/
-
public void deleteEmployeer(int id);
-
-
/**
-
* 注意要和Employeer.xml的方法名对应
-
*/
-
public void updateEmployeer(Employeer employeer);
-
-
}
（1）增加命令
上一讲【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 中的方式：
-
/**
-
* 增加
-
*/
-
public static void addEmployeer(Employeer employeer){
-
SqlSession session =
null;
-
try {
-
session = sqlSessionFactory.openSession();
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//返回值是记录条数
-
int resultCount = session.insert(
"com.mucfc.model.EmployeerMapper.addEmployeer", employeer );
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System.out.printf(
"当前插入的employeer_id :%d 当前插入数据库中条数:%d " , employeer.getEmployeer_id() ,resultCount);
//获取插入对象的id
-
System.out.println(
"");
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session.commit() ;
-
}
finally {
-
session.close();
-
}
-
-
}
改成以接口编程的方式：
-
/**
-
* 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() ;
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}
finally {
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session.close();
-
}
-
-
}
（2）删除命令
上一讲【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 中的方式：
-
/**
-
* 删除
-
*
-
*/
-
public static void deleteEmployeer(int id){
-
SqlSession session =
null;
-
try {
-
session = sqlSessionFactory.openSession();
-
//返回值是记录条数
-
int resultCount=session.delete(
"com.mucfc.model.EmployeerMapper.deleteEmployeer",id);
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System.out.println(
"当前删除数据库中条数: "+resultCount);
//获取插入对象的id
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session.commit() ;
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}
finally {
-
session.close();
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}
-
}
改成以接口编程的方式：
-
/**
-
* 删除
-
*
-
*/
-
public static void deleteEmployeer(int id){
-
SqlSession session =
null;
-
try {
-
session = sqlSessionFactory.openSession();
-
EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
-
employeerMapper.deleteEmployeer(id);
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session.commit() ;
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}
finally {
-
session.close();
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}
-
}
（3）查找命令
上一讲【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 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);
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}
finally {
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session.close();
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}
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}
改成以接口编程的方式：
-
/**
-
* 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
上一讲【Mybatis】Mybatis入门概述及第一个Mybatis实例实现增删改查 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 {
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session.close();
-
}
-
-
}
改成以接口编程的方式：
-
/**
-
* 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();
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}
-
-
}
这是一个完整的测试：
-
package com.mucfc.test;
-
-
import java.io.IOException;
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import java.io.Reader;
-
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import org.apache.ibatis.io.Resources;
-
import org.apache.ibatis.session.SqlSession;
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import org.apache.ibatis.session.SqlSessionFactory;
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import org.apache.ibatis.session.SqlSessionFactoryBuilder;
-
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import com.mucfc.mapper.EmployeerMapper;
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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();
-
}
-
-
}
-
/**
-
* 删除
-
*
-
*/
-
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(
"产品一部");
-
employeer1.setEmployeer_worktype(
"开发工程师");
-
-
Employeer employeer2=
new Employeer();
-
employeer2.setEmployeer_name(
"张三");
-
employeer2.setEmployeer_age(
30);
-
employeer2.setEmployeer_department(
"产品二部");
-
employeer2.setEmployeer_worktype(
"测试工程师");
-
-
Employeer employeer3=
new Employeer();
-
employeer3.setEmployeer_name(
"小王");
-
employeer3.setEmployeer_age(
22);
-
employeer3.setEmployeer_department(
"产品三部");
-
employeer3.setEmployeer_worktype(
"数据分析师");
-
-
-
Employeer employeer4=
new Employeer();
-
employeer4.setEmployeer_name(
"明明");
-
employeer4.setEmployeer_age(
22);
-
employeer4.setEmployeer_department(
"财会部");
-
employeer4.setEmployeer_worktype(
"财务人员");
-
-
//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(
"产品四部");
-
updateEmployeer(employeer2);
-
-
}
-
-
}
测试结果：
插入了4条数据，ID为25~28
然后27号被删除
29号被修改
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