8 mp实现自动填充.png
1.数据库表中添加自动填充字段
在User表中添加datetime类型的新的字段 create_time、update_time
2.实体上添加注解
@Data public class User { ...... @TableField(fill = FieldFill.INSERT) private Date createTime; //@TableField(fill = FieldFill.UPDATE) @TableField(fill = FieldFill.INSERT_UPDATE) private Date updateTime; 11 }
3.实现元对象处理器接口
元对象就是数据库的原始数据
注意：不要忘记添加 @Component 注解
package com.atguigu.mybatisplus.handler; import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler; import org.apache.ibatis.reflection.MetaObject; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import java.util.Date; @Component public class MyMetaObjectHandler implements MetaObjectHandler { private static final Logger LOGGER = LoggerFactory.getLogger(MyMetaObjectHandler.class); @Override public void insertFill(MetaObject metaObject) { LOGGER.info("start insert fill ...."); this.setFieldValByName("createTime", new Date(), metaObject); this.setFieldValByName("updateTime", new Date(), metaObject); } @Override public void updateFill(MetaObject metaObject) { LOGGER.info("start update fill ...."); this.setFieldValByName("updateTime", new Date(), metaObject); } }
