mybatis完整增删改查入门实例

mybatis完整增删改查入门实例

编程步骤

①创建Java工程。

②导入jar包。

③创建sqlMapConfig.xml配置文件，这是mybatis的入口。

④创建数据库，数据库表user_c,插入测试记录。

⑤创建PO对象user.java.

⑥创建映射文件user.xml.

⑦创建测试类。

mybatis的占位符

#{遵循Java变量名规范的名称均可}

导入核心jar包

mybatis-3.2.2.jar

依赖jar包

asm-3.3.1.jar
cglib-2.2.2.jar
commons-logging-1.1.1.jar
javassist-3.17.1-GA.jar
log4j-1.2.17.jar
slf4j-api-1.7.5.jar
slf4j-log4j12-1.7.5.jar

核心配置文件sqlMapConfig.xml

事务：JDBC/MANAGED

数据源：UNPOOLED/POOLED/JNDI

<?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>
<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/mybatisdb?characterEncoding=UTF-8"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>

<mappers>
<mapper resource="cn/nwtxxb/mybatis/domain/User.xml"/>
</mappers>
</configuration>

创建数据库

创建mybatisdb数据库，创建User表。

sql语句：

create table USER_C

(

ID   varchar(40) not null,

NAME varchar(30),

AGE  int,

ADDRESS  varchar(200),

primary key (ID)

);

insert  into `user_c`(`id`,`name`,`age`,`address`)

values ('1','夏言',73,'桂州村'),

('2','严嵩',87,'分宜县城介桥村'),

('3','徐阶',80,'明松江府华亭县'),

('4','高拱',66,'河南省新郑市高老庄村'),

('5','张居正',58,'江陵');

配置映射文件User.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">
<!-- 命名空间用于查找 -->
<mapper namespace="cn.nwtxxb.mybatis">

<!-- 替代，语句中的内容,简写 -->
<sql id="cols">
id,name,age,address
</sql>
<!--  查询所有记录 -->
<select id="listAll" resultType="cn.nwtxxb.domain.User">
select <include refid="cols"/> from   user_c
</select>

<!-- 查询一个用户 -->  <!--  别名替代，简写-->
<select id="getOne" parameterType="string" resultType="aliasesUser">
select <include refid="cols"/> from   user_c  where id= #{id}
</select>

<!--  插入一个用户 -->
<insert id="insertOne" parameterType="cn.nwtxxb.domain.User" >
insert into user_c( <include refid="cols"/> ) values (#{id},#{name},#{age},#{address})
</insert>

<!--  更新一个用户 -->
<insert id="updateOne" parameterType="cn.nwtxxb.domain.User" >
update user_c set name=#{name},age=#{age},address=#{address} where id=#{id}
</insert>

<!-- 删除一个用户 -->
<update id="deleteOne" parameterType="cn.nwtxxb.domain.User" >
delete from user_c where id= #{id}
</update>
</mapper>

PO对象User.java

package cn.nwtxxb.domain;

public class User {
private String id;
pri
4000
vate String name;
private Integer age;
private String address;
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getId() {
return id;
}
public void setId(String 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;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
}

}

测试类

package cn.nwtxxb.test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;
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.Before;
import org.junit.Test;

import cn.nwtxxb.domain.User;

public class TestMybatis {

SqlSessionFactory sqlSessionFactory;

@Before
public void initFactory() throws IOException
{
String resource = "sqlMapConfig.xml";

InputStream inputStream = Resources.getResourceAsStream(resource);

sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
}

@Test
public  void testListAll()
{
SqlSession session=sqlSessionFactory.openSession();
List<User> users=session.selectList("cn.nwtxxb.mybatis.listAll");
System.out.println(users.size());
}
@Test
public void testQueryOne()
{
SqlSession session=sqlSessionFactory.openSession();
User user=session.selectOne("cn.nwtxxb.mybatis.getOne", 1);
System.out.println(user);
}
//事务需要程序员处理
@Test
public void testInsertOne()
{
User u=new User();
u.setId(UUID.randomUUID().toString());
u.setName("sbsbb");
u.setAge(18);
u.setAddress("china");
SqlSession session=sqlSessionFactory.openSession();
int count=session.insert("cn.nwtxxb.mybatis.insertOne", u);
session.commit();
System.out.println(count);
}

@Test
public void testUpdateOne()
{
SqlSession session=sqlSessionFactory.openSession();
User u=new User();
//u=session.selectOne("cn.nwtxxb.mybatis.getOne", "2");
u.setId("2");
u.setName("clclclclclcfei");
u.setAge(100);
u.setAddress("USA");
int count=session.update("cn.nwtxxb.mybatis.updateOne", u);
session.commit();
System.out.println(count);
}
@Test
public void testDeleteOne()
{
SqlSession session=sqlSessionFactory.openSession();
User u=new User();
u.setId("2");
int count=session.delete("cn.nwtxxb.mybatis.deleteOne", u);
session.commit();
System.out.println(count);
}

}