mybits最基本的例子---------实现增删改查

1，项目结构

2，表单结构

3，项目代码

3.1 book.java

package com.entity;

public class Book {

	private int bookid;
	private String bookname;
	private String bookauthor;
	private int bookprice;

	public Book() {
		super();
	}

	public Book(int bookid, String bookname, String bookauthor, int bookprice) {
		super();
		this.bookid = bookid;
		this.bookname = bookname;
		this.bookauthor = bookauthor;
		this.bookprice = bookprice;
	}

	public Book(String bookname, String bookauthor, int bookprice) {
		super();
		this.bookname = bookname;
		this.bookauthor = bookauthor;
		this.bookprice = 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 String getBookauthor() {
		return bookauthor;
	}

	public void setBookauthor(String bookauthor) {
		this.bookauthor = bookauthor;
	}

	public int getBookprice() {
		return bookprice;
	}

	public void setBookprice(int bookprice) {
		this.bookprice = bookprice;
	}

}

BookMapper.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"><mapper namespace="com.mapper.BookMapper"><span style="white-space:pre">	</span><resultMap id="mapBook" type="com.entity.Book">		<id property="bookid" column="id"></id>		<result property="bookname" column="username"></result>		<result property="bookprice" column="price"></result>		<result property="bookauthor" column="author"></result>	</resultMap></span></strong>	<select id="findById" parameterType="int" resultMap="mapBook">		select *		from book where id = #{id}	</select>	<delete id="del" parameterType="int">		delete * from book where id =		#{id}	</delete>	<insert id="add" parameterType="com.entity.Book">		insert into book		values(null,#{bookname},#{bookauthor},#{bookprice})	</insert>	<select id="show" resultMap="mapBook">		select * from book	</select></mapper>

Configuration.xml

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration>	<environments default="development">		<environment id="development">			<transactionManager type="JDBC"></transactionManager>			<dataSource type="POOLED">				<property name="driver" value="com.mysql.jdbc.Driver"></property>				<property name="url" value="jdbc:mysql://localhost:3306/<span style="color:#ff6666;"><mysqlDb></span>?characterEncoding=utf-8"></property>				<property name="username" value=mysqlnam"></property>				<property name="password" value="mysqlpassword"></property>			</dataSource>		</environment>	</environments>		<mappers>		<mapper resource="com/mapper/BookMapper.xml"></mapper>	</mappers></configuration>

3.4 MysqlSessionFactory

package com.util;

import java.io.IOException;
import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;


public class MysqlSessionFactory {
	static SqlSession session;
	public SqlSession getSqlSession(){
		try {
			Reader reader = Resources.getResourceAsReader("Configuration.xml");
			SqlSessionFactory  sessionFactory = new SqlSessionFactoryBuilder().build(reader);
			session = sessionFactory.openSession();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return session;
	}

}

Test.java

package com.util;import org.apache.ibatis.session.SqlSession;import com.entity.*;public class Test {		public static void main(String[] args) {				MysqlSessionFactory mysqlSessionFactory = new MysqlSessionFactory();		SqlSession session = mysqlSessionFactory.getSqlSession();				System.out.println(session);				Book book = (Book)session.selectOne("com.mapper.BookMapper.findById",25);		System.out.println(book);		session.commit();						Book bookadd = new Book(0, "java","mike",90);		session.insert("com.mapper.BookMapper.add",bookadd);		session.commit();									}}

以上是整个demo的所有源代码！

只想说这一部分

1,book.javav中的属性名与mysql中book table中字段名字不匹配：

<resultMap id="mapBook" type="com.entity.Book">
	<id property="bookid" column="id"></id>
	<result property="bookname" column="username"></result>
	<result property="bookprice" column="price"></result>
	<result property="bookauthor" column="author"></result>
</resultMap>

resulteMap 是为了解决book.javav中的属性名与mysql中book table中字段名字不匹配，无法进行数据的填充！

2,命名空间

<mapper namespace="com.mapper.BookMapper">

这个是service的名字，不要写错，另外service的方法名也要和配置文件的方法名一样。

总体感觉没什么好说的！

1，读取配置文件获得SqlsessionFactory

2，通过SqlsessionFactory获得sqlsession

那涉及到一个问题：配置文件

配置文件:Configtion.xml

这个文件定义了关于数据源的配置

<environments default="development">
		<environment id="development">
			<transactionManager type="JDBC"></transactionManager>
			<dataSource type="POOLED">
				<property name="driver" value="com.mysql.jdbc.Driver"></property>
				<property name="url" <span style="font-family: Arial, Helvetica, sans-serif;">value="jdbc:mysql://localhost:3306/</span><span style="font-family: Arial, Helvetica, sans-serif;"></property></span>

				<property name="username" value="mysqlnam"></property>				<property name="password" value="mysqlpassword"></property>			</dataSource>		</environment>	</environments>

那么这里有了连接mysql数据库的必要信息但是我们的目的是通过java语句操作数据库

封装数据库为一个POJO，也就是book.java

我们通过操作book对象操作数据库的记录！

那么类有了就会有类与数据库中表的关系的对应配置信息BookMapper.xml

其实这里与其说配置的是表和类的关系还不如说是对sql语句的关系的配置

参数是BOOK对象，与BOOK类建立了联系通过强大的#{}让字段名与类属性相关联，实现数据的填充！

不得不说，java的封装就是强！

类属性与表字段之间联系的确定，实现了对象和表中数据的关联！

个人见解，望广大网友批评指正！

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