Mybatis的CRUD（增删改查）
1.pom.xml
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.41</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.6</version>
</dependency>
</dependencies>
2.SqlMapperConfig.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPEconfiguration
PUBLIC"-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<!--mybatis的主配置文件-->
<configuration>
<!--配置环境-->
<environments default="mysql">
<!--配置mysql环境-->
<environment id="mysql">
<!--配置事务的类型-->
<transactionManager type="JDBC"></transactionManager>
<!--配置数据源（连接池）-->
<dataSource type="POOLED">
<!--配置连接数据库的4个基本信息-->
<property name="driver" value="com.mysql.jdbc.Driver"></property>
<property name="url" value="jdbc:mysql://localhost:3306/zml?useUnicode=true&characterEncoding=utf-8"></property>
<property name="username" value="root"></property>
<property name="password" value="root"></property>
</dataSource>
</environment>
</environments>
<!--指定映射配置文件的位置，映射配置文件指的是每个dao独立的配置文件-->
<mappers>
<mapper resource="dao/UserDao.xml"></mapper>
</mappers>
</configuration>
3.Users.java
package entity;
public class Users {
private int id;
private String username;
private String password;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
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;
}
@Override
public String toString() {
return "Users{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
}
4.UserVo.java
package entity;
public class UserVo {
private Users users;
public Users getUsers() {
return users;
}
public void setUsers(Users users) {
this.users = users;
}
}
5.UserDao.java
package dao;
import entity.UserVo;
import entity.Users;
import java.util.List;
public interface UserDao {
List<Users> findAll();
Users find(int id);
void save(Users users);
void update(Users users);
void delete(int id);
List<Users> findVague(String name);
int count();
List<Users> findVo(UserVo vo);
}
6.UserDao.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPEmapper
PUBLIC"-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="dao.UserDao">
<!--查询所有-->
<select id="findAll" resultType="entity.Users">
select * from users
</select>
<!--根据ID查询-->
<select id="find" resultType="entity.Users">
select * from users where id=#{id}
</select>
<!--增加-->
<insert id="save" parameterType="entity.Users">
<!--查询新增用户的ID-->
<selectKey keyProperty="id" keyColumn="id" resultType="int" order="AFTER">
select last_insert_id()
</selectKey>
insert into users(username,password) values(#{username},#{password})
</insert>
<!--根据ID进行修改-->
<update id="update" parameterType="entity.Users">
update users set username=#{username},password=#{password} where id=#{id}
</update>
<!--根据ID进行删除-->
<delete id="delete" parameterType="entity.Users">
delete from users where id=#{id}
</delete>
<!--模糊查询-->
<select id="findVague" resultType="entity.Users">
-- select * from users where username like '%${value}%'
select * from users where username like #{name}
</select>
<!--查询用户总数-->
<select id="count" resultType="int">
select count(id) from users
</select>
<!--将实体类封装到另一个实体类中的模糊查询-->
<select id="findVo" resultType="entity.Users">
select * from users where username like #{users.username}
</select>
</mapper>
7.UserTest.java
package test;
import dao.UserDao;
import entity.UserVo;
import entity.Users;
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.After;
import org.junit.Before;
import org.junit.Test;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
public class UserTest {
private InputStream in;
private SqlSession sqlSession;
private UserDao UserDaoImpl;
@Before
public void init() throws IOException {
//1.读取配置文件
in= Resources.getResourceAsStream("SqlMapperConfig.xml");
//2.创建SqlSessionFactory工厂
SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder();
SqlSessionFactory factory=builder.build(in);
//3.使用工厂生产SqlSession对象
sqlSession=factory.openSession();
//4.使用SqlSession创建dao接口的代理对象
UserDaoImpl=sqlSession.getMapper(UserDao.class);
}
@After
public void destroy() throws IOException {
//提交事务
sqlSession.commit();
//6.释放资源
sqlSession.close();
in.close();
}
/**
* 查询所有
* @throws IOException
*/
@Test
public void findall() throws IOException {
//5.使用代理对象执行方法
List<Users> users=UserDaoImpl.findAll();
for(Users u:users){
System.out.println(u);
}
}
/**
* 增加
*/
@Test
public void save(){
Users users=new Users();
users.setUsername("哈哈哈");
users.setPassword("456");
UserDaoImpl.save(users);
}
/**
* 根据ID查询并修改
*/
@Test
public void update(){
Users u=UserDaoImpl.find(15);
u.setPassword("456");
u.setUsername("小喵");
UserDaoImpl.update(u);
}
/**
* 根据id进行删除
*/
@Test
public void delete(){
UserDaoImpl.delete(16);
}
/**
* 模糊查询，查询所有名字中有小的用户
* @throws IOException
*/
@Test
public void findVague() throws IOException {
//5.使用代理对象执行方法
List<Users> users=UserDaoImpl.findVague("%小%");
for(Users u:users){
System.out.println(u);
}
}
/**
* 查询用户总数
*/
@Test
public void count(){
int c=UserDaoImpl.count();
System.out.println(c);
}
/**
* 将实体类封装到另一个实体类中的模糊查询
*/
@Test
public void findVo(){
UserVo vo=new UserVo();
Users users=new Users();
users.setUsername("%小%");
vo.setUsers(users);
List<Users> list=UserDaoImpl.findVo(vo);
for(Users u:list){
System.out.println(u);
}
}
}