1.使用场景

save操作之前实体类中id为null，save之后自动返回带id的实体类

@Override public ChartPagePanel save(ChartPagePanel entity) { UserDetails user = SecurityContextHolder.getUserDetails(); entity.setCreateUser(user.getUsername()); entity.setLastModifyUser(user.getUsername()); //entity中的id为null chartPagePanelMapper.save(entity); //经过save操作后自动返回带id的entity // savePanelManage(entity); 其中的entity带有id savePanelManage(entity); return entity; } @Transactional public void savePanelManage(ChartPagePanel entity){ if(entity.getChartPageManges()!=null && entity.getChartPageManges().size()>0) { Map<String, Object> map = new HashMap<>(); for (int i = 0; i < entity.getChartPageManges().size(); i++) { int manageId = entity.getChartPageManges().get(i).getId(); map.put("manageId", manageId); map.put("panelId", entity.getId()); chartPagePanelManageMapper.save(map); } } }

2.原理在Mybatis配置了useGeneratedKeys=“true” keyProperty=“id”

<insert id="save" parameterType="com.centrin.generator.entity.ChartPagePanel" useGeneratedKeys="true" keyProperty="id"> insert into chart_page_panel ( `parent_id`, `position`, `name`, `create_time`, `create_user`, `last_modify_time`, `last_modify_user` ) values ( #{parentId}, #{position}, #{name}, NOW(), #{createUser}, NOW(), #{lastModifyUser} ) </insert>