Mybatis-实现增删改查
通过Mybatis持久化框架实现对数据库表的增删改查的简单例子
（个人心得：我感觉学习一个框架可以先去了解它大致的运行流程，然后再去学习其填充的东西，这样更加容易理解而且在学的过程中也会联系起来。不然一开始就看框架的一些详细解释感觉好难懂）
StyleCategory实体类
package com.mybatis.entity;
/**
* @author lyx
*
* 2015-9-2下午7:07:57
*
*com.mybatis.entity.StyleCategory
*
*/
public class StyleCategory {
private int styleId;
private String styleName;
public int getStyleId() {
return styleId;
}
public void setStyleId(int styleId) {
this.styleId = styleId;
}
public String getStyleName() {
return styleName;
}
public void setStyleName(String styleName) {
this.styleName = styleName;
}
public StyleCategory(int styleId, String styleName) {
super();
this.styleId = styleId;
this.styleName = styleName;
}
public StyleCategory(String styleName) {
super();
this.styleName = styleName;
}
public StyleCategory() {
super();
}
}
styleMapper.xml （sql映射文件）
<?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.mybatis.entity.StyleMapper">
<!-- sql标签 表示可以被其他语句复用的SQL块-->
<sql id="queryFields">
styleId,styleName
</sql>
<!-- -->
<resultMap type="StyleCategory" id="styleMap">
<!-- 主键映射 -->
<id property="styleId" column="styleId" javaType="int" />
<!-- 数据库字段到实体类属性的映射 -->
<result property="styleName" column="styleName"/>
</resultMap>
<!-- 根据style查询 -->
<select id="getStyleById" parameterType="int" resultType="StyleCategory" >
select
<include refid="queryFields"></include>
from STYLE_CATEGORY where styleId=#{styleId}
</select>
<!-- 查询全部 -->
<select id="queryAllInfo" resultType="StyleCategory" resultMap="styleMap">
select
*
from STYLE_CATEGORY
</select>
<!-- 插入 -->
<!-- 如果使用的是表中自定义的主键就不需要的添加 useGeneratedKeys="true" 否则会报错：列名无效，Error getting generated key or setting result to parameter object-->
<!-- 设置是否使用JDBC的getGenereatedKeys方法获取主键并赋值到keyProperty设置的领域模型属性中。MySQL和SQLServer执行auto-generated key field，
因此当数据库设置好自增长主键后，可通过JDBC的getGeneratedKeys方法获取。但像Oralce等不支持auto-generated key field的数据库就不能用这种方法获取主键了 -->
<insert id="addStyleInfo" parameterType="StyleCategory" keyProperty="styleId">
<!-- <selectKey resultType="StyleCategory" order="BEFORE" keyProperty="styleId">
select SEQUENCE_STYLECATEGORY.nextval as STYLEID from dual;
</selectKey> -->
insert into STYLE_CATEGORY (styleId,styleName) values (SEQUENCE_STYLECATEGORY.nextval,#{styleName})
</insert>
<!-- 更新 -->
<update id="updateStyleInfo" parameterType="StyleCategory" >
update STYLE_CATEGORY set styleName=#{styleName} where styleId=#{styleId}
</update>
<!-- 删除 -->
<delete id="deleteStyleInfoById" parameterType="int">
delete from STYLE_CATEGORY where styleId =#{styleId}
</delete>
</mapper>
mybatis主配置文件
<?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> <!-- 设置别名 --> <!-- typeAliases标签 是写实体类的别名，写了之后可以在写类的映射文件例如<select>标签中的属性就可以不用写实体的具体路径直接用别名 --> <typeAliases> <typeAlias type="com.mybatis.entity.StyleCategory" alias="StyleCategory"/> </typeAliases> <!-- 数据库配置 --> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"></transactionManager> <dataSource type="POOLED"> <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"></property> <property name="driver" value="oracle.jdbc.driver.OracleDriver"></property> <property name="username" value="lyx"></property> <property name="password" value="lyx"></property> </dataSource> </environment> </environments> <!-- 映射文件 --> <mappers> <mapper resource="mapper/styleMapper.xml"/> </mappers> </configuration>
测试类
package test;
import java.io.IOException;
import java.io.Reader;
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.mybatis.entity.StyleCategory;
public class MainTest {
public static void main(String[] args) throws IOException
{
//读取配置文件
Reader reader =Resources.getResourceAsReader("mybatis-config.xml");
SqlSessionFactory sqlSession =new SqlSessionFactoryBuilder().build(reader);
//打开session会话
SqlSession session = sqlSession.openSession();
//查询
StyleCategory style = session.selectOne("com.mybatis.entity.StyleMapper.getStyleById",2);
System.out.println("style:"+style.getStyleId()+","+style.getStyleName());
//删除
int deleteNum=session.delete("com.mybatis.entity.StyleMapper.deleteStyleInfoById",22);
if(deleteNum>0)
{
System.out.println( deleteNum +"删除成功！");
}
//更新
StyleCategory updateStyle = new StyleCategory(2,"刘育新");
int updateNum=session.update("com.mybatis.entity.StyleMapper.updateStyleInfo",updateStyle);
if(updateNum>0)
{
System.out.println( updateNum +"更新成功！");
}
//插入数据
StyleCategory insertStyle = new StyleCategory("大中华");
int insertNum =session.insert("com.mybatis.entity.StyleMapper.addStyleInfo",insertStyle);
if(insertNum>0)
{
System.out.println(insertNum+"插入成功");
}
//查询全部
List<StyleCategory> list=session.selectList("com.mybatis.entity.StyleMapper.queryAllInfo");
for (StyleCategory styleCategory : list) {
System.out.println(styleCategory.getStyleId()+":"+styleCategory.getStyleName());
}
//提交session会话，否则操作数据库无效
session.commit();
}
}