There are a couple of ways that I know of. You can use "Update Multiple Records", select "Assign calculated value" and use this formula...

if NumberField = 1 then
number(replace(text(NumberField), "1", "0"))
else
NumberField
end

You can attach this code to a Button or run it in the Console...

for r in select YourTable do
if r.NumberField = 1 then r.(NumberField := 0) end
end

@sean I am trying to use replace('E-mail', "<", "") in Trigger after update but this replace function is not working in my case. I actually want to get string between these brackets <somestring>. Is there any solution for this? 

Dev twentyZen, you can do something like this…

replace('E-mail, "<", "<" + somestring)

replace(extractx('E-mail', "(?=\<)(.*?)(?=\>)"), "<", "")

Hi Uwe,

It looks like you just added pattern matching to Dev's misuse of the replace function. From the manual...

Both of you are just replacing "<" with an empty string.

Hello Sean
You are actually right about that.
The correct regex would be:
(?<=\<)(.*?)(?=\>).
However, Ninox cannot do a 'positive lookbehind' in this case.
Therefore: (?=\<)(.*?)(?=\>).
The "" in replace(extractx(title, "(?=\<)(.*?)(?=\>)"), "<", "") does not create a space , but replaces the < character with 'nothing', so removes the < character.

Well, that's an interesting explanation, but it's irrelevant for the stated requirement.