MyBatis注解开发

2023-11-22 18:51:04

MyBatis注解开发

注解开发

步骤

  • 1.创建接口和编写操作方法

  • 2.在核心配置文件中配置映射关系

    <?xml version="1.0" encoding="UTF-8" ?>

<!--MyBitis的DTD约束，定义xml标签约束,使开发者按照定义书写-->
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<!--configuration 根标签-->
<configuration>
    <!--引入数据库配置文件-->
    <properties resource="jdbc.properties" />
    <!--配置LOG4J-->
    <settings>
        <setting name="logImpl" value="log4j"/>
    </settings>
    <!--起别名-->
    <typeAliases>
        <package name="com.cmy.bean" />
    </typeAliases>
    <!--environments配置数据库环境，环境可以有很多个，而default属性则是指定某个环境-->
    <environments default="mysql1">
        <!--    environment数据库环境，id属性：唯一标识    -->
        <environment id="mysql1">
            <!--transactionManager事务管理，type 采用JDBC默认的事务管理-->
            <transactionManager type="JDBC" />
            <!--dataSource数据库源信息 type属性 连接池-->
            <dataSource type="POOLED">
                <!--property 获取数据库连接的配置信息-->
                <property name="driver" value="${driver}" />
                <property name="url" value="${url}" />
                <property name="username" value="${username}" />
                <property name="password" value="${password}" />
            </dataSource>
        </environment>
    </environments>
    <!--mappers配置映射关系-->
    <mappers>
        <package name="com.cmy.mapper"/>
    </mappers>
</configuration>

    使用<package>标签配置映射关系，指定对应接口所在包的映射关系

  • 3.编写测试类

查询操作

  • 1.创建接口和查询方法

    package com.cmy.mapper;

import com.cmy.bean.Book;
import org.apache.ibatis.annotations.Select;

import java.util.List;

/**
 * @author chenmingyong
 */
public interface BookMapper {
	/**
	 * 查询全部图书信息
	 * @return 结果集
	 */
	@Select("SELECT * FROM BOOK")
	public abstract List<Book> selectAll();
}

  • 2.在核心配置文件中配置映射关系

  • 3.测试文件

    InputStream is = null;
SqlSession sqlSession = null;
try {
    is = Resources.getResourceAsStream("MyBatisConfig.xml");
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
    sqlSession = sqlSessionFactory.openSession(true);
    BookMapper mapper = sqlSession.getMapper(BookMapper.class);
    List<Book> list = mapper.selectAll();
    for (Book book : list) {
        System.out.println(book);
    }
}
catch (Exception e){
    e.printStackTrace();
}
finally {
    if(sqlSession != null){
        sqlSession.close();
    }
    if(is != null){
        try {
            is.close();
        }
        catch (Exception e){
            e.printStackTrace();
        }
    }
}

增加操作

  • 1.创建接口和增加方法

    package com.cmy.mapper;

import com.cmy.bean.Book;
import org.apache.ibatis.annotations.Insert;

import java.util.List;

/**
 * @author chenmingyong
 */
public interface BookMapper {
	/**
	 * 插入一条数据
	 * @param book 图书类实例对象
	 * @return 返回影响行数
	 */
	@Insert("INSERT INTO book VALUES (#{book_id},#{book_name},#{book_author},#{book_publisher})")
	public abstract Integer insert(Book book);
}

  • 2.在核心配置文件中配置映射关系

  • 3.测试文件

    InputStream is = null;
SqlSession sqlSession = null;
try {
    is = Resources.getResourceAsStream("MyBatisConfig.xml");
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
    sqlSession = sqlSessionFactory.openSession(true);
    BookMapper mapper = sqlSession.getMapper(BookMapper.class);
    Book book = new Book(4, "测试", "测试", "测试");
    Integer result = mapper.insert(book);
    System.out.println(result);
}
catch (Exception e){
    e.printStackTrace();
}
finally {
    if(sqlSession != null){
        sqlSession.close();
    }
    if(is != null){
        try {
            is.close();
        }
        catch (Exception e){
            e.printStackTrace();
        }
    }
}

修改操作

  • 1.创建接口和修改方法

    package com.cmy.mapper;

import com.cmy.bean.Book;
import org.apache.ibatis.annotations.Update;

import java.util.List;

/**
 * @author chenmingyong
 */
public interface BookMapper {
	/**
	 * 更新一条数据
	 * @param book 图书类实例对象
	 * @return 返回影响行数
	 */
	@Update("UPDATE book SET book_name=#{book_name},book_author=#{book_author},book_publisher=#{book_publisher}  WHERE book_id=#{book_id}")
	public abstract Integer update(Book book);
}

  • 2.在核心配置文件中配置映射关系

  • 3.测试文件

    InputStream is = null;
SqlSession sqlSession = null;
try {
    is = Resources.getResourceAsStream("MyBatisConfig.xml");
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
    sqlSession = sqlSessionFactory.openSession(true);
    BookMapper mapper = sqlSession.getMapper(BookMapper.class);
    Book book = new Book(4, "测试11", "测试11", "测试11");
    Integer result = mapper.update(book);
    System.out.println(result);
}
catch (Exception e){
    e.printStackTrace();
}
finally {
    if(sqlSession != null){
        sqlSession.close();
    }
    if(is != null){
        try {
            is.close();
        }
        catch (Exception e){
            e.printStackTrace();
        }
    }
}

删除操作

  • 1.创建接口和删除方法

    package com.cmy.mapper;

import com.cmy.bean.Book;
import org.apache.ibatis.annotations.Delete;

import java.util.List;

/**
 * @author chenmingyong
 */
public interface BookMapper {
	/**
	 * 删除一条数据
	 * @param book_id 图书id
	 * @return 返回影响行数
	 */
	@Delete("DELETE FROM book WHERE book_id=#{book_id}")
	public abstract Integer delete(Integer book_id);
}

  • 2.在核心配置文件中配置映射关系

  • 3.测试文件

    InputStream is = null;
SqlSession sqlSession = null;
try {
    is = Resources.getResourceAsStream("MyBatisConfig.xml");
    SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
    sqlSession = sqlSessionFactory.openSession(true);
    BookMapper mapper = sqlSession.getMapper(BookMapper.class);
    Integer result = mapper.delete(6);
    System.out.println(result);
}
catch (Exception e){
    e.printStackTrace();
}
finally {
    if(sqlSession != null){
        sqlSession.close();
    }
    if(is != null){
        try {
            is.close();
        }
        catch (Exception e){
            e.printStackTrace();
        }
    }
}
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