有正则高手吗？ 帮忙解决一下这个问题

Question

现在有一条sql语句

select ID as id,Name as name,IP as ip,lat,lon,0 as type from trk.devs_v2 where type=0 union all select id,signalName as name,ip,lat,lng as lon,99 as type from yc_signal.signal union all

想使用正则让最后一个union all去掉 而不是去掉所有的union all

想要的结果为
select ID as id,Name as name,IP as ip,lat,lon,0 as type from trk.devs_v2 where type=0 union all select id,signalName as name,ip,lat,lng as lon,99 as type from yc_signal.signal

有正则大神帮帮忙呗! 万分感谢

Answer 1

let str = "union albdfdfdfunion alaadunion al";
let reg = str.replace(/(union al)$/,'');
console.log(reg)

Answer 2

Javascript

"select ID as id,Name as name,IP as ip,lat,lon,0 as type from trk.devs_v2 where type=0 union all select id,signalName as name,ip,lat,lng as lon,99 as type from yc_signal.signal union all".replace(/union\sall(?!.*?union\sall)/g, "")

PHP

preg_replace("/union\sall(?!.*?union\sall)/", "", "select ID as id,Name as name,IP as ip,lat,lon,0 as type from trk.devs_v2 where type=0 union all select id,signalName as name,ip,lat,lng as lon,99 as type from yc_signal.signal union all")

Answer 3

没懂，只union all的话。。直接str.replace(/ union all$/,'')不就行了？