mysql - SQL 语句中的 SQL 语句

Question

我希望这条语句返回有两个以上站点的系统，我已经走到这一步了，但我不知道下一步该怎么做。所有这些都会返回 regionID 小于 1100001 的每个系统。至少我的想法是正确的吗？

SELECT DISTINCT mapSolarSystems.regionID,solarSystemID,solarSystemName,x,z,security 
FROM mapSolarSystems 
WHERE mapSolarSystems.regionID <11000001  
AND 
2 < (SELECT COUNT(*) FROM stations,mapSolarSystems
 WHERE mapSolarSystems.solarSystemID=stations.systemid)

Answer 1

看看这个是否有效:

SELECT DISTINCT mapSolarSystems.regionID,solarSystemID,solarSystemName,x,z,security 
FROM mapSolarSystems m
join stations s on m.solarSystemID = s.systemid
WHERE mapSolarSystems.regionID <11000001  
AND select COUNT(*) FROM stations >2

或者像这样:

SELECT DISTINCT 
mapSolarSystems.regionID,solarSystemID,solarSystemName,x,z,security 
FROM mapSolarSystems m
join (select sistemId ,count(systemid) from station group by sistemId having 
      count(sistemId) > 2) X on m.solarSystemID = X.systemid
WHERE mapSolarSystems.regionID <11000001