Notes

主题

08.注解开发 ​

简单的 sql 语句使用注解，复杂的 sql 语句和结果集映射使用 xml 配置文件

1.save ​

接口方法

java
@Insert("insert into user(name, pwd) values(#{name}, #{pwd})")
int save(User user);

测试用例

java
@Test
public void save(){
    // 1.获取sqlSession对象
    SqlSession sqlSession = MyBatisUtil.getSqlSession();
    // 2.获取需要的mapper接口的代理对象
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    // 3.调用对应的方法执行操作
    User user = new User();
    user.setName("SAVE ID");
    user.setPwd("123");
    int save = mapper.save(user);
    System.out.println(save);
    System.out.println(user);
    // 4.提交事务
    sqlSession.commit();
    // 5.关闭sqlSession
    sqlSession.close();
}

控制台打印

shell
[main] [org.hong.mapper.UserMapper.save]-[DEBUG] ==>  Preparing: insert into user(name, pwd) values(?, ?)
[main] [org.hong.mapper.UserMapper.save]-[DEBUG] ==> Parameters: SAVE ID(String), 123(String)
[main] [org.hong.mapper.UserMapper.save]-[DEBUG] <==    Updates: 1
1
User(id=null, name=SAVE ID, pwd=123)

2.select ​

接口方法

java
@Select("select * from user where id = #{id}")
User get(int id);

测试用例

java
@Test
public void get(){
    // 1.获取sqlSession对象
    SqlSession sqlSession = MyBatisUtil.getSqlSession();
    // 2.获取需要的mapper接口的代理对象
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    // 3.调用对应的方法执行操作
    User user = mapper.get(1);
    System.out.println(user);
    // 4.提交事务
    sqlSession.commit();
    // 5.关闭sqlSession
    sqlSession.close();
}

控制台打印

shell
[main] [org.hong.mapper.UserMapper.get]-[DEBUG] ==>  Preparing: select * from user where id = ?
[main] [org.hong.mapper.UserMapper.get]-[DEBUG] ==> Parameters: 1(Integer)
[main] [org.hong.mapper.UserMapper.get]-[DEBUG] <==      Total: 1
User(id=1, name=谢禹宏, pwd=654321)

3.update ​

接口方法

java
@Update("update user set name = #{name}, pwd = #{pwd} where id = #{id}")
int update(User user);

测试用例

java
@Test
public void update(){
    // 1.获取sqlSession对象
    SqlSession sqlSession = MyBatisUtil.getSqlSession();
    // 2.获取需要的mapper接口的代理对象
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    // 3.调用对应的方法执行操作
    User user = mapper.get(1);
    user.setPwd("987654");
    int update = mapper.update(user);
    System.out.println(user);
    // 4.提交事务
    sqlSession.commit();
    // 5.关闭sqlSession
    sqlSession.close();
}

控制台打印

shell
[main] [org.hong.mapper.UserMapper.get]-[DEBUG] ==>  Preparing: select * from user where id = ?
[main] [org.hong.mapper.UserMapper.get]-[DEBUG] ==> Parameters: 1(Integer)
[main] [org.hong.mapper.UserMapper.get]-[DEBUG] <==      Total: 1
[main] [org.hong.mapper.UserMapper.update]-[DEBUG] ==>  Preparing: update user set name = ?, pwd = ? where id = ?
[main] [org.hong.mapper.UserMapper.update]-[DEBUG] ==> Parameters: 谢禹宏(String), 987654(String), 1(Integer)
[main] [org.hong.mapper.UserMapper.update]-[DEBUG] <==    Updates: 1
User(id=1, name=谢禹宏, pwd=987654)

4.delete ​

接口方法

java
@Delete("delete from user where id = #{id}")
int delete(int id);

测试用例

java
@Test
public void delete(){
    // 1.获取sqlSession对象
    SqlSession sqlSession = MyBatisUtil.getSqlSession();
    // 2.获取需要的mapper接口的代理对象
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    // 3.调用对应的方法执行操作
    int delete = mapper.delete(10);
    System.out.println(delete);
    // 4.提交事务
    sqlSession.commit();
    // 5.关闭sqlSession
    sqlSession.close();
}

控制台打印

shell
[main] [org.hong.mapper.UserMapper.delete]-[DEBUG] ==>  Preparing: delete from user where id = ?
[main] [org.hong.mapper.UserMapper.delete]-[DEBUG] ==> Parameters: 10(Integer)
[main] [org.hong.mapper.UserMapper.delete]-[DEBUG] <==    Updates:
0

5.最终版 ​

5.1 Mapper 接口 ​

java
package org.hong.mapper;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import org.hong.pojo.User;

import java.util.List;


public interface UserMapper {
    @Insert("insert into user(name, pwd) values(#{name}, #{pwd})")
    int save(User user);

    @Select("select * from user where id = #{id}")
    User get(int id);

    @Update("update user set name = #{name}, pwd = #{pwd} where id = #{id}")
    int update(User user);

    @Delete("delete from user where id = #{id}")
    int delete(int id);
}

5.2 测试用例 ​

java
package org.hong.test;

import org.apache.ibatis.session.SqlSession;
import org.hong.mapper.UserMapper;
import org.hong.pojo.User;
import org.hong.util.MyBatisUtil;
import org.junit.Test;

public class AnnotationTest {
    @Test
    public void save(){
        // 1.获取sqlSession对象
        SqlSession sqlSession = MyBatisUtil.getSqlSession();
        // 2.获取需要的mapper接口的代理对象
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        // 3.调用对应的方法执行操作
        User user = new User();
        user.setName("SAVE ID");
        user.setPwd("123");
        int save = mapper.save(user);
        System.out.println(save);
        System.out.println(user);
        // 4.提交事务
        sqlSession.commit();
        // 5.关闭sqlSession
        sqlSession.close();
    }

    @Test
    public void get(){
        // 1.获取sqlSession对象
        SqlSession sqlSession = MyBatisUtil.getSqlSession();
        // 2.获取需要的mapper接口的代理对象
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        // 3.调用对应的方法执行操作
        User user = mapper.get(1);
        System.out.println(user);
        // 4.提交事务
        sqlSession.commit();
        // 5.关闭sqlSession
        sqlSession.close();
    }

    @Test
    public void update(){
        // 1.获取sqlSession对象
        SqlSession sqlSession = MyBatisUtil.getSqlSession();
        // 2.获取需要的mapper接口的代理对象
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        // 3.调用对应的方法执行操作
        User user = mapper.get(1);
        user.setPwd("987654");
        int update = mapper.update(user);
        System.out.println(user);
        // 4.提交事务
        sqlSession.commit();
        // 5.关闭sqlSession
        sqlSession.close();
    }

    @Test
    public void delete(){
        // 1.获取sqlSession对象
        SqlSession sqlSession = MyBatisUtil.getSqlSession();
        // 2.获取需要的mapper接口的代理对象
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        // 3.调用对应的方法执行操作
        int delete = mapper.delete(10);
        System.out.println(delete);
        // 4.提交事务
        sqlSession.commit();
        // 5.关闭sqlSession
        sqlSession.close();
    }
}

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