1.UserMapper.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">
<!--namespace:名称空间-->
<!--找到接口类UserMapper.java-->
<mapper namespace="com.xxxx.mapper.UserMapper">
<select id="selectAll" resultType="com.xxxx.entity.User">
select * from tb_user
</select>
<select id="selectByUid" resultType="com.xxxx.entity.User">
select * from tb_user
where uid= #{uid};
</select>
<!-- 条件查询 -->
<select id="selectBytiaojian" resultType="com.xxxx.entity.User">
select * from tb_user
where uname like #{uname};
</select>
<insert id="add" useGeneratedKeys="true" keyProperty="uid">
insert into tb_user (uname,upwd,uage)
values (#{uname},#{upwd},#{uage});
</insert>
<update id="update1">
update tb_user set
uname=#{uname},
upwd=#{upwd},
uage=#{uage}
where uid=#{uid};
</update>
<update id="update2">
update tb_user
<set>
<if test="uname != null and uname!=''">
uname=#{uname},
</if>
<if test="upwd !=null and upwd!=''">
upwd=#{upwd},
</if>
<if test="uage !=null">
uage=#{uage}
</if>
</set>
where uid=#{uid};
</update>
<delete id="deleteByUid">
delete from tb_user where uid=#{uid};
</delete>
<!--注意：mybatis会将数组参数封装成一个Map集合
默认：array=数组
如果想修改：可以使用@Param注解，就可以使用uids了
-->
<delete id="deleteByUids">
delete from tb_user where uid
in
<foreach collection="uids" item="uid" separator="," open="(" close=")">
#{uid}
</foreach>
</delete>
<select id="selectBytiaojian2" resultType="com.xxxx.entity.User">
select * from tb_user
where uname=#{arg0}
and upwd=#{param2}
</select>
</mapper>
2.UserMapper.java
package com.xxxx.mapper;
import com.xxxx.entity.User;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface UserMapper {
public List<User> selectAll();
public User selectByUid(int uid);
public User selectBytiaojian(String uname);
public void add(User user);
//返回修改的行数
public int update1(User user);
public void update2(User user);
public void deleteByUid(int id);
public void deleteByUids(@Param("uids") int[] uids);
/**
* 多个参数：封装成Map集合
* map.put("arg0",参数值1)
* map.put("param1",参数值1)
* map.put("arg1",参数值2)
* map.put("param2",参数值2)
*/
//不写注解的情况
public User selectBytiaojian2(String uname,String upwd);
}
3.MyTeat.java
package com.xxxx.test;
import com.xxxx.entity.User;
import com.xxxx.mapper.UserMapper;
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 java.io.IOException;
import java.io.InputStream;
import java.util.List;
public class MyTest {
// @Test为啥不行
public void testselectAll() throws IOException {
//1.加载mybatis的核心配置文件，获取SqlSessionFactory对象
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
//3.执行sql 前面一长串是命名空间+id（在UserMapper.xml里面可以找到）
// List<User> users=sqlSession.selectList("com.xxxx.mapper.UserMapper.selectAll");
//获取UserMapper接口的代理对象(这个过程是由mybatis内部实现的)
UserMapper userMapper =sqlSession.getMapper(UserMapper.class);
List<User> users=userMapper.selectAll();
System.out.println(users);
//4.释放资源
sqlSession.close();
}
// @Test为啥不行
public void testselectByUid() throws IOException {
//接收参数
int id=2;
//1.加载mybatis的核心配置文件，获取SqlSessionFactory对象
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
//3.执行sql 前面一长串是命名空间+id（在UserMapper.xml里面可以找到）
// List<User> users=sqlSession.selectList("com.xxxx.mapper.UserMapper.selectAll");
//获取UserMapper接口的代理对象(这个过程是由mybatis内部实现的)
UserMapper userMapper =sqlSession.getMapper(UserMapper.class);
User user = userMapper.selectByUid(id);
System.out.println(user.getUid()+" "+user.getUname()+" "+user.getUpwd()+" "+ user.getUage());
//4.释放资源
sqlSession.close();
}
public void testselectBytiaojian() throws IOException {
String uname1 = "mi";
// 注意：模糊查询需要在两端加%%
String uname2 ="%"+uname1+"%";
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession();
//3.执行sql 前面一长串是命名空间+id（在UserMapper.xml里面可以找到）
// List<User> users=sqlSession.selectList("com.xxxx.mapper.UserMapper.selectAll");
//获取UserMapper接口的代理对象(这个过程是由mybatis内部实现的)
UserMapper userMapper =sqlSession.getMapper(UserMapper.class);
//模糊查询
User user = userMapper.selectBytiaojian(uname2);
System.out.println(user.getUid()+" "+user.getUname()+" "+user.getUpwd()+" "+ user.getUage());
//4.释放资源
sqlSession.close();
}
public void testadd() throws IOException {
// int uid=4;
String uname="hi";
String upwd="666666";
int uage=50;
User user=new User();
user.setUname(uname);
user.setUpwd(upwd);
user.setUage(uage);
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession(true);
//3.执行sql 前面一长串是命名空间+id（在UserMapper.xml里面可以找到）
// List<User> users=sqlSession.selectList("com.xxxx.mapper.UserMapper.selectAll");
//获取UserMapper接口的代理对象(这个过程是由mybatis内部实现的)
UserMapper userMapper =sqlSession.getMapper(UserMapper.class);
userMapper.add(user);
int uid=user.getUid();
System.out.println(uid);
//删除后要手动提交事物
sqlSession.commit();
//如果不想的话可以在第2步的时候，写成这样，就会自动提交事物了
// SqlSession sqlSession = sqlSessionFactory.openSession(true);
//4.释放资源
sqlSession.close();
}
public void testupdate1() throws IOException {
int uid=7;
String uname="hxixixi";
String upwd="223344";
int uage=4;
User user=new User();
user.setUid(uid);
user.setUname(uname);
user.setUpwd(upwd);
user.setUage(uage);
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession(true);
//3.执行sql 前面一长串是命名空间+id（在UserMapper.xml里面可以找到）
// List<User> users=sqlSession.selectList("com.xxxx.mapper.UserMapper.selectAll");
//获取UserMapper接口的代理对象(这个过程是由mybatis内部实现的)
UserMapper userMapper =sqlSession.getMapper(UserMapper.class);
int count=userMapper.update1(user);
System.out.println(count);
//删除后要手动提交事物
sqlSession.commit();
//如果不想的话可以在第2步的时候，写成这样，就会自动提交事物了
// SqlSession sqlSession = sqlSessionFactory.openSession(true);
//4.释放资源
sqlSession.close();
}
public void testupdate2() throws IOException {
int uid=7;
String uname="hxixixi";
String upwd="223344";
int uage=99;
User user=new User();
user.setUid(uid);
user.setUname(uname);
// user.setUpwd(upwd);
user.setUage(uage);
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession(true);
//3.执行sql 前面一长串是命名空间+id（在UserMapper.xml里面可以找到）
// List<User> users=sqlSession.selectList("com.xxxx.mapper.UserMapper.selectAll");
//获取UserMapper接口的代理对象(这个过程是由mybatis内部实现的)
UserMapper userMapper =sqlSession.getMapper(UserMapper.class);
userMapper.update2(user);
//删除后要手动提交事物
sqlSession.commit();
//如果不想的话可以在第2步的时候，写成这样，就会自动提交事物了
// SqlSession sqlSession = sqlSessionFactory.openSession(true);
//4.释放资源
sqlSession.close();
}
public static void main(String[] args) throws IOException {
int[] uids={3,6};
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取SqlSession对象，用它来执行sql
SqlSession sqlSession = sqlSessionFactory.openSession(true);
//3.执行sql 前面一长串是命名空间+id（在UserMapper.xml里面可以找到）
// List<User> users=sqlSession.selectList("com.xxxx.mapper.UserMapper.selectAll");
//获取UserMapper接口的代理对象(这个过程是由mybatis内部实现的)
UserMapper userMapper =sqlSession.getMapper(UserMapper.class);
userMapper.deleteByUids(uids);
//删除后要手动提交事物
sqlSession.commit();
//如果不想的话可以在第2步的时候，写成这样，就会自动提交事物了
// SqlSession sqlSession = sqlSessionFactory.openSession(true);
//4.释放资源
sqlSession.close();
}
}
4.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">
<configuration>
<!--propertie 标签中的配置可以供整个文件使用，任何位置都可以引入其中的配置值-->
<properties resource="mysql.properties"/>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<!-- <mapper resource="com/xxxx/mapper/UserMapper.xml"/>-->
<!-- mapper代理方式：扫描包 -->
<package name="com.xxxx.mapper"/>
</mappers>
</configuration>
5.mysql.properties
driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/course?serverTimezone=UTC&useSSL=false&characterEncoding=UTF-8
username=root
password=123456
