Spring Mvc那点事---(11)Spring Mvc之mybatis增删改查

    数据库的基本操作就是增删改查，这一节我们演示下通过mybatis怎样操作数据库以及怎样在mybaits中配置SQL语句。我们知道，在mybaits中每个实体对象都对应一个Mapper文件，我们在mapper中配置好相关的增删改查语句,

 

<?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="mapping.skusMapper">   <!-- 指定查询SQL, parameterType是传入参数类型，resultType是返回结果-->    <select id="getSku" parameterType="int"         resultType="dto.skus">        SELECT * FROM skus WHERE  id=#{id}    </select>    <!-- 添加 -->     <insert id="addSku" parameterType="dto.skus">       INSERT INTO skus (skuname,skucode)  VALUES (#{SkuName},#{SkuCode})     </insert>          <!-- 删除 -->     <delete id="delSku" parameterType="java.lang.String">              DELETE FROM skus WHERE SkuCode=#{_parameter}     </delete>          <!-- 修改 -->     <update id="updateSku" parameterType="dto.skus">       UPDATE skus SET skuname=#{SkuName} WHERE SkuCode=#{SkuCode}     </update>            <!-- 查询全部 -->     <select id="getList"  resultType="dto.skus">       SELECT Id,SkuName,SkuCode FROM skus      </select>          </mapper>

    以上包括基本的增删改查和查询集合。其中parameterType是传入的参数类型，resultType是返回的结果类型，注意当个查询和查询所有结果,resultType的值是一样的。

   接下来，我们看看怎么操作Mapper文件。

      

@Controller@RequestMapping("/Home")public class HomeController {@Resource(name="applePhone")    private IMobilePhone phone;@RequestMapping(value="index")public String Index(){String msg=phone.PhoneBrand();System.out.print(msg);  String resource = "/conf.xml";        //加载mybatis的配置文件        InputStream inputstream =this.getClass().getResourceAsStream(resource);               SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputstream);              SqlSession session = sessionFactory.openSession();               String statesql= "mapping.skusMapper.getSku";//在skusMapper.xml中有命名空间+方法名                skus sku = session.selectOne(statesql, 1);        System.out.println(sku.getSkuName());                return "index";}@RequestMapping(value="AddSku")public String AddSku(){    String resource = "/conf.xml";        //加载mybatis的配置文件        InputStream inputstream =this.getClass().getResourceAsStream(resource);               SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputstream);              SqlSession session = sessionFactory.openSession();               String statesql= "mapping.skusMapper.addSku";//在skusMapper.xml中有命名空间+方法名        skus sku=new skus();        sku.setSkuName("黑色手表");        sku.setSkuCode("00002");        int result = session.insert(statesql,sku);        session.commit();            session.close();        System.out.println(result);    return "index";}@RequestMapping(value="DelSku")public String DelSku(){    String resource = "/conf.xml";        //加载mybatis的配置文件        InputStream inputstream =this.getClass().getResourceAsStream(resource);               SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputstream);              SqlSession session = sessionFactory.openSession();               String statesql= "mapping.skusMapper.delSku";//在skusMapper.xml中有命名空间+方法名                int result = session.delete(statesql,"00002");        session.commit();            session.close();        System.out.println(result);    return "index";}@RequestMapping(value="UpdateSku")public String UpdateSku(){    String resource = "/conf.xml";        //加载mybatis的配置文件        InputStream inputstream =this.getClass().getResourceAsStream(resource);               SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputstream);              SqlSession session = sessionFactory.openSession();               String statesql= "mapping.skusMapper.updateSku";//在skusMapper.xml中有命名空间+方法名                skus sku=new skus();        sku.setSkuName("黑色手表男士款式");        sku.setSkuCode("00002");                        int result = session.update(statesql, sku);        session.commit();            session.close();        System.out.println(result);    return "index";}@RequestMapping(value="List")public String List(){    String resource = "/conf.xml";        //加载mybatis的配置文件        InputStream inputstream =this.getClass().getResourceAsStream(resource);               SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(inputstream);              SqlSession session = sessionFactory.openSession();               String statesql= "mapping.skusMapper.getList";//在skusMapper.xml中有命名空间+方法名                       java.util.List<skus> listResult= session.selectList(statesql);        session.commit();            session.close();                    for(dto.skus item:listResult)            {                   System.out.print(item.getId()+"--"+item.getSkuCode()+"--"+item.getSkuName());                System.out.print("--------------");            }               return "index";}}

    上面的代码演示了具体的增删改查操作方法。注意一点，如果插入数据中的中文为乱码，要把数据库连接配置为utf8,如下

  <property name="url" value="jdbc:mysql://localhost:3306/erp?useUnicode=true&amp;characterEncoding=utf8" />

  &amp;代表&符号。

</pre><p>     表结构如下</p><p>   <pre name="code" class="sql">CREATE TABLE `skus` (  `Id` int(11) NOT NULL AUTO_INCREMENT,  `SkuName` varchar(50) DEFAULT NULL,  `SkuCode` varchar(50) DEFAULT NULL,  PRIMARY KEY (`Id`)) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8