1.Mybatis實現CRUD操作
domain包下User類就用了ORM思想。
Dao接口裏面的方法:
package com.dao;
import com.domain.User;
import java.util.List;
public interface IUserDao {
List<User> findAll();
void saveUser(User user);
void updateUser(User user);
void deleteUser(Integer userId);
User findById(Integer userId);
List<User> findByName(String username);
int findTotal();
}
主配置文件:
<?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">
<!--mybaits的主配置文件-->
<configuration>
<environments default="mysql">
<!--配置mysql環境-->
<environment id="mysql">
<!--配置事務類型-->
<transactionManager type="JDBC"></transactionManager>
<!--配置數據源(連接池)-->
<dataSource type="POOLED">
<!--配置數據源(連接池)的基本信息-->
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/406"/>
<property name="username" value="root"/>
<property name="password" value="123456789"/>
</dataSource>
</environment>
</environments>
<!--指定映射配置文件的位置,映射配置文件指的是每個dao配置的文件-->
<mappers>
<mapper resource="com/dao/IUserDao.xml"></mapper>
</mappers>
</configuration>
映射配置文件:
<?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.dao.IUserDao">
<!--查詢所有-->
<select id="findAll" resultType="com.domain.User">
select * from user;
</select>
<!--保存用戶-->
<insert id="saveUser" parameterType="com.domain.User">
<!--配置插入數據後,獲取插入數據的id-->
<selectKey keyProperty="id" keyColumn="id" resultType="int" order="AFTER">
select last_insert_id();
</selectKey>
insert into user(username,address,sex,birthday)values(#{username},#{address},#{sex},#{birthday});
</insert>
<!--更新用戶-->
<update id="updateUser" parameterType="com.domain.User">
update user set username=#{username},address=#{address},sex=#{sex},birthday=#{birthday} where id =#{id}
</update>
<!--刪除用戶-->
<delete id="deleteUser" parameterType="Integer">
delete from user where id =#{uid}
</delete>
<!--根據id查詢用戶-->
<select id="findById" parameterType="INT" resultType="com.domain.User">
select * from user where id=#{uid}
</select>
<!--根據名稱模糊查詢的語法-->
<select id="findByName" parameterType="String" resultType="com.domain.User">
<!--select * from user where username like #{name}-->
select * from user where username like '%${value}%'
</select>
<!--獲取用戶的總記錄條數-->
<select id="findTotal" resultType="int">
select count(id) from user;
</select>
</mapper>
測試類代碼:
package com.test;
import ...
public class MybatisTest {
private InputStream in;
private SqlSession sqlSession;
private IUserDao userDao;
@Before//用於在測試方法執行之前執行
public void init()throws Exception{
//1.讀取配置文件,生成字節輸入流
in =Resources.getResourceAsStream("SqlMapConfig.xml");
//2.獲取SqlSessionFactory
SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(in);
//3.獲取SqlSession對象
sqlSession = factory.openSession();
//4.獲取dao代理對象
userDao = sqlSession.getMapper(IUserDao.class);
}
@After//用於在測試方法執行之後執行
public void destroy()throws Exception{
//提交事務
sqlSession.commit();
//6.釋放資源
sqlSession.close();
in.close();
}
@Test
public void testFindAll(){
//5.執行查詢所有方法
List<User> users=userDao.findAll();
for (User user:users){
System.out.println(user);
}
}
@Test
public void testSave(){
User user = new User();
user.setUsername("mybatis saveuser");
user.setAddress("SZ");
user.setSex("男");
user.setBirthday(new Date());
System.out.println("保存操作之前,"+user);
//5.執行保存方法
userDao.saveUser(user);
System.out.println("保存操作之後"+user);
}
@Test
public void testUpdate(){
User user = new User();
user.setId(41);
user.setUsername("mybatis update");
user.setAddress("SZZ");
user.setSex("女");
user.setBirthday(new Date());
//5.執行更新方法
userDao.updateUser(user);
}
@Test
public void testDelete(){
//5.執行刪除方法
userDao.deleteUser(41);
}
@Test
public void testFindOne(){
//5.執行查詢一個方法
User user = userDao.findById(42);
System.out.println(user);
}
@Test
public void testFindByName(){
//5.執行模糊查詢方法
// List<User> users = userDao.findByName("%my%");
List<User> users = userDao.findByName("my");
for (User user : users){
System.out.println(user);
}
}
@Test
public void testFindTotal(){
//5.執行查詢總記錄條數方法
int count =userDao.findTotal();
System.out.println(count);
}
}
模糊查詢的細節:
第二張圖 控制檯後面是where like ?