Comparing item with others in the column

[Boris_Maximov]

I’d like the numbers in a numeric column to be unique. Is there a way to check with a formula whether the new entry already exists in the column, no matter how many items there are? The result can appear in the column itself if possible, or in an extra field like for errors.

I mean if there is a field with
1
2
3
…and I add a fourth item, which is
1
again
– it should not be possible or return a warning

[kuovonne]

A formula field cannot access other values in the same column; it can only access other values in the same record/row.

You can the summary bar to determine uniqueness. Note that this will only show uniqueness for the records in the view. The summary bar will not take into considerations any hidden records.

You can also use an autonumber field to guarantee uniqueness.