MyBatis实现增删改查

MyBatis是一个基于Java的持久层框架，专注是sql，需要我们程序员自己编写sql语句，sql的修改优化比较方便，Mybatis也是一个不完全的ORM框架，自己写sql，能够完成输入、输出映射。

应用场景：适用于需求变化比较多的项目

与hibernate比较：

Hibernate:是一个标准的ORM（ 对象关系映射）,入门超级简单，不用写sql语句，sql自动生成了。

  Hibernate:应用场景：适用于变化不多的大中小型项目，比如：OA（办公自动化）、CRM（客户关系管理）、后台管理系统…

环境准备：

　　需要导入的jar文件，如下图：

还需要导入log4j.properties文件

log4j.rootLogger=DEBUG, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

整个包和文件关系结构如图：

1.SqlMapConfig.xml

<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!-- 和spring整合后 environments配置将废除  mybatis-config.xml-->
    <environments default="development">
        <environment id="development">
        <!-- 使用jdbc事务管理-->
            <transactionManager type="JDBC" />
        <!-- 数据库连接池-->
            <dataSource type="POOLED">
                <property name="driver" value="oracle.jdbc.driver.OracleDriver" />
                <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" />
                <property name="username" value="dsx" />
                <property name="password" value="admin" />
            </dataSource>
        </environment>
    </environments>
    
    <!-- 加载mapper.xml -->
    <mappers>
    <!-- com.entity下面 
        <mapper resource="com/entity/User.xml" />-->
        <mapper resource="Book.xml" />
    </mappers>
    
</configuration>

2.Book实体类

package com.test.book;

import java.util.Date;

/**
 * 
 * @author Mr
 * 图书实体类
 */
public class Book {
    /*  INT PRIMARY KEY NOT NULL,
      varchar2(100) default null,
      DATE default null,
      Number(8,2) default null*/
    private int bookid;
    private String bookname;
    private Date bookdate;
    private double bookprice;
    public int getBookid() {
        return bookid;
    }
    public void setBookid(int bookid) {
        this.bookid = bookid;
    }
    public String getBookname() {
        return bookname;
    }
    public void setBookname(String bookname) {
        this.bookname = bookname;
    }
    public Date getBookdate() {
        return bookdate;
    }
    public void setBookdate(Date bookdate) {
        this.bookdate = bookdate;
    }
    public double getBookprice() {
        return bookprice;
    }
    public void setBookprice(double bookprice) {
        this.bookprice = bookprice;
    }
    public Book() {
        super();
        // TODO Auto-generated constructor stub
    }
    public Book( String bookname, Date bookdate, double bookprice) {
        super();
        this.bookname = bookname;
        this.bookdate = bookdate;
        this.bookprice = bookprice;
    }
    public Book(int bookid, String bookname, Date bookdate, double bookprice) {
        super();
        this.bookid = bookid;
        this.bookname = bookname;
        this.bookdate = bookdate;
        this.bookprice = bookprice;
    }
    @Override
    public String toString() {
        return "Book的序号是:" + bookid + "
书名是:" + bookname
                + "
图书出版日期是:" + bookdate + "
图书的价格是:" + bookprice + "]";
    }
    
}

3.book.xml配置文件编写

<?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命名空间，为了对sql语句进行隔离，方便管理 ，mapper开发dao方式，使用namespace有特殊作用 -->
<mapper namespace="test">
<!-- 添加图书 -->
<insert id="insertBook" parameterType="com.test.book.Book">
    INSERT INTO book VALUES(seq_book_id.nextval,#{bookname},#{bookdate},#{bookprice})
</insert>
<!-- 删除一本书 -->
<delete id="delBook" parameterType="java.lang.Integer">
    DELETE book WHERE bookid=#{bookid}
</delete>
<!-- 更新一本图书 -->
<update id="upBook" parameterType="com.test.book.Book">
    UPDATE book SET bookname=#{bookname},bookprice=#{bookprice} WHERE bookid=#{bookid}
</update>
<!-- 查询一本图书 -->
<select id="findBookById" parameterType="java.lang.Integer" resultType="com.test.book.Book">
    SELECT * FROM book WHERE bookid=#{bookid}
</select>
<!-- 根据书名模糊查询 -->
<select id="findBookByName" parameterType="java.lang.String" resultType="com.test.book.Book">
    SELECT * FROM book WHERE bookname LIKE '%${value}%'
</select>

</mapper>

4.测试类Test1.java

package com.test.test;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;

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 com.test.book.Book;

/**
 * 
 * @author Mr
 * mybatis图书测试类
 */
public class Test1 {

    public static void main(String[] args) {
        try {
            //找到mybatis文件并加载
            String resource="SqlMapConfig.xml";
            //读取这个文件
            InputStream inputStream = Resources.getResourceAsStream(resource);
            //创建sqlSessionFactory会话工厂
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
            //操作数据库的sqlsession
            SqlSession sqlSession = sqlSessionFactory.openSession();
            
    /*        //添加图书
            Book book = new Book("MyBatis入门到精通", new Date(), 68.58);
            sqlSession.insert("test.insertBook", book);
            sqlSession.commit();*/
            
        /*    //删除一本图书
            sqlSession.delete("test.delBook",2);
            //提交事务
            sqlSession.commit();*/
            
        /*    //更新一本图书
            Book book = new Book();
            book.setBookid(5);
            book.setBookname("Linux从入门到精通");
            book.setBookprice(59.45);
            
            sqlSession.update("test.upBook", book);
            //提交事务
            sqlSession.commit();*/
            
        /*    //查询一本书
            Book book = sqlSession.selectOne("test.findBookById", 7);
            System.out.println(book);*/
            
            //根据书名模糊查询
            List<Book> list = sqlSession.selectList("test.findBookByName", "java");
            for (Book book : list) {
                System.out.println(book);
            }
            
            
            //释放资源
            sqlSession.close();
            
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            System.out.println("
执行ok");
        }

    }

}

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