union的结果集，为什么不是第一个结果集的内容在前面

悬赏园豆：10 [已解决问题] 解决于 2015-06-30 16:13

具体的问题看截图吧！！！

select StationTitle from AkLineStation
inner join AkLineProcess on AkLineProcess.Id=AkLineStation.LineProcessId
where AkLineProcess.LineTitle='Line1' and AkLineStation.StationTitle='EL1-2'

select StationTitle from AkLineStation
inner join AkLineProcess on AkLineProcess.Id=AkLineStation.LineProcessId
where AkLineProcess.LineTitle='Line1' and lower(left(AkLineStation.StationTitle,2))='el' and AkLineStation.StationTitle<>'EL1-2'

select StationTitle from AkLineStation
inner join AkLineProcess on AkLineProcess.Id=AkLineStation.LineProcessId
where AkLineProcess.LineTitle='Line1' and AkLineStation.StationTitle='EL1-2'
union
select StationTitle from AkLineStation
inner join AkLineProcess on AkLineProcess.Id=AkLineStation.LineProcessId
where AkLineProcess.LineTitle='Line1' and lower(left(AkLineStation.StationTitle,2))='el' and AkLineStation.StationTitle<>'EL1-2'