[TOC] # 目录 ## Mybatis ### 例子 ```java @Transactional(rollbackFor = Exception.class) public Integer createOrder() throws Exception { // 省略无关代码 ... // 插入 order 记录 Order order = Order.builder() .orderAmount(product.getPrice().multiply(new BigDecimal(purchaseProductNum))) .orderStatus(1) .receiverName("xxx") .receiverMobile("13800138000") .createTime(new Date()) .createUser("xxx") .updateTime(new Date()) .updateUser("xxx") .build(); orderMapper.insertSelective(order); // 根据上面插入的order记录获取主键ID orderItemMapper.insertSelective(OrderItem.builder() .orderId(order.getId()) .productId(product.getId()) .productPrice(product.getPrice()) .purchaseNum(purchaseProductNum) .createUser("xxx") .createTime(new Date()) .updateUser("xxx") .updateTime(new Date()) .build() ); return order.getId(); } } ``` <br>  ### 办法一 OrderMapper.xml ```xml <insert id="insertSelective" parameterType="com.example.distributedemo.model.Order" useGeneratedKeys="true" keyProperty="id"> <!-- 省略无关代码 ... --> </insert> ``` ### 办法二 ```xml <insert id="insertSelective" parameterType="com.example.distributedemo.model.Order"> <selectKey resultType="java.lang.Long" order="AFTER" keyProperty="id"> SELECT LAST_INSERT_ID() </selectKey> <!-- 省略无关代码 ... --> </insert> ``` <br>