方式有两种,第一种如下:
A数据表中多个字段对应B数据表的ID,
现在要把B表的其他字段一起查询出来
一、数据表:
1、SPEED_DETECTION_ROAD
一、数据表:
1、SPEED_DETECTION_ROAD
它的 START_POINT_ID 和 END_POINT_ID字段对应下面表的ID,
2、SECTION_INFO:
二、sql语句
SELECT section1.SECTION_NAME AS sectionStart, section2.SECTION_NAME AS sectionEND FROM A表 AS road inner join B表 AS section1 on road.START_POINT_ID = section1.SECTION_ID inner join B表 AS section2 on road.END_POINT_ID = section2.SECTION_ID
思路:
SPEED_DETECTION_ROAD表有两个字段是SECTION_INFO表的ID,因此,Inner Join 数据表SECTION_INFO两次(join方式看业务)
三、查询结果
方法二:
sql: 其实就是嵌套子查询实现的。
SELECT road.road_name, (select SECTION_NAME from B表 where road.START_POINT_ID = b.SECTION_ID ) as sectionStart, (select SECTION_NAME from B表 where road.END_POINT_ID = b.SECTION_ID) as sectionEND FROM A表 AS road
参考文章:https://blog.csdn.net/weixin_36013896/article/details/122403107
标签:POINT,SECTION,数据表,字段,个表,sql,ID,road From: https://www.cnblogs.com/isme-zjh/p/18134752