Data Validation

[Nadhirah]

Hi, How do I stop user from entering same information using a new row for a column. For example, we have trade description and we would like the newly added trade description to be different so that there will be no duplicate data with different unique ID. Any ideas? 

[Suvrutt_Gurjar · Accepted solution]

You can prevent duplicate values for a column by using the approach described in the article below and expression described below in the valid_if of the column. Please be aware that this approach will not work in multi user environment when two users try to simultaneously update with the same value. But generally such occurrences of simultaneous update maybe rare. Of course you will be the best judge of how frequently this is likely to happen and if impact is severe.

ISBLANK(
FILTER(
"Table Name",
([_THIS] = [Trade Description])
)
- LIST([_THISROW])
)

List expressions - AppSheet Help

[Nadhirah]

I will try this later. Thankss!