详解Java MyBatis 插入数据库返回主键

User user = new User(); 
user.setUserName("chenzhou"); 
user.setPassword("xxxx"); 
user.setComment("测试插入数据返回主键功能"); 
 
System.out.println("插入前主键为："+user.getUserId()); 
userDao.insertAndGetId(user);//插入操作 
System.out.println("插入后主键为："+user.getUserId()); 

<insert id="insertAndGetId" useGeneratedKeys="true" keyProperty="userId" parameterType="com.chenzhou.mybatis.User">
  insert into user(userName,password,comment)
  values(#{userName},#{password},#{comment})
</insert>

  <!-- 插入一个商品 -->
  <insert id="insertProduct" parameterType="domain.model.ProductBean" >
    <selectKey resultType="java.lang.Long" order="AFTER" keyProperty="productId">
     SELECT LAST_INSERT_ID()
   </selectKey>
    INSERT INTO t_product(productName,productDesrcible,merchantId)values(#{productName},#{productDesrcible},#{merchantId});
  </insert>

  @Override
  public Long insertProduct(ProductBean productBean) {
    // TODO Auto-generated method stub
    SqlSession session = MybatisJDBCUtil.currentSession();

    ProductIDao productIDao = session.getMapper(ProductIDao.class);// 这里*.class
                                    // 必须对应DAO的接口层
    return productIDao.insertProduct(productBean);
    
  }

session.commit();    
MybatisJDBCUtil.closeSession();

  @Override
  public void insertProduct(ProductBean productBean) {
    // TODO Auto-generated method stub
    SqlSession session = MybatisJDBCUtil.currentSession();

    ProductIDao productIDao = session.getMapper(ProductIDao.class);// 这里*.class
                                   // 必须对应DAO的接口层
    productIDao.insertProduct(productBean);
    
    session.commit(); 
    
    MybatisJDBCUtil.closeSession();  
  }