Seems that it’s a very common use case to allow user’s to create usernames (or similar). Would be great to have a way to tick a box in text component to prevent duplicate strings from being created so that the usernames are actually unique - (same as IG where you get an error that the username is not available). I understand this is probably a massive over-simplification of developing this feature. 
While we wait for this to be available, a workaround would be using the sign up tab visibility we have talked about many times on here, make a relation from the input username to the username column, and don’t let the user advance when the relation is not empty,
2 Likes
We can give then an error message and keep them on the username til they enter one that has not been used? and would there be a lag?
Yes that is the way to go. And no lag here, that will be instantly.
The only risk is that if you use that username for relations then there will be multiple results, because you’re actually storing that duplicated username in your data. Personally I always use email just to make sure.
Yeah, I would rather just wait on this one. I don’t love workarounds, especially if they create lag or get too complicated! 
1 Like
I do this in my apps which require unique usernames and have zero lags but surely it has a slightly longer workaround. It’s a self-relation with the username column and then a roll-up to count the number of relations. I use a simple condition using the rollup column to show the error text.
2 Likes