How long has it been there?

存在多久了？

youdao

Oh, how long has it been since I have seen one!

我有多久没有看见苹果流啊！

youdao

How long has it been since you released a new version of your software?

从你发行最新版本的软件到现在有多久了？

youdao

"There has been a long and vigorous debate about this. And that is how it should be.

VOA: standard.2009.08.11

There has been a long discussion about what people owe each other and how okay it is to try to make money.

曾经有一次很长的讨论,是关于自己欠别人多少,而自己应该赚多少才合适

耶鲁公开课 - 金融市场课程节选

How long has it been since I rode a horse?

NEWYORKER: The Insufferable Gaucho

Memory loss can be a factor, and they may not realize how long it has been since their last bath.

CNN: Is bathing just once a week healthy?

Reading the history linked above will give you some background as to why and how long it has been fought.

FORBES: Why Has No One Been Appointed The Winner Of Armstrong's Seven Tours?