Honestly, I don't know what to do with this thread.
Simply using any search (google, SCN search, ... ) provides plenty of threads that deal with the very same question and provide solutions.
Like this how to check to see if a value is numeric in sap hana
or this HANA Instr function to check for numbers?
or this Find numbers in a string
This means, the current thread is not just showing that the author didn't do his 'homework' but also that this is a breach of the The SCN Rules of Engagement.
So, normally, and that's what I do often (unfortunately I have to do it far too often), I click on "Alert Moderator" and report the thread for "Failed to search".
However, this really feels like picking up crap at the beach. It's everyone's responsibility and OK to do if it is only a few items to pick up every time you're there.
But if there's more and more crap and your picking up doesn't seem to yield and improvement, what do you do?
Not come back to this beach?
That might work if you're a tourist there and you're on vacation.
But what if you live at the beach?
I consider myself a resident here on SCN and threads like this one are the litter/rubbish/crap of communities. No, you cannot totally prevent it from happening and I don't have a miracle cure for it, but it sure annoys the fun out of me.
So, there you have it.