I was thinking of " IN " ( apply to values) with a " NOT " before " IN " to have """NOT IN"" instead " EXIST " ( apply work if one record exist in a table ) like you .....
ALTER TABLE Table
ADD CONSTRAINT uniquecolvalue AS
[VALUE] NOT IN ( SELECT [VALUE] FROM [Table]);
but don't work because the actual VALUE ( dynamic value that will be insert in value column ) that manifold handle should be accessible using specific syntax and so his name can't be be [VALUE] but @[VALUE] or something else ... Do we need to create a Virtual table for the select ? ( use a join )
<value> IN (<query>)
Returns True (1) if the value occurs in the results of the query.
? 'Durango' IN (SELECT [NAME] FROM [Mexico Table])
? 'Vermont' IN (SELECT [NAME] FROM [Mexico Table])
<value> IN (<value>, ...)
Returns True (1) if the first value occurs in the list of values.
? 'Tom' IN ('Tom', 'Dick', 'Harry')
? 'John' IN ('Tom', 'Dick', 'Harry')
Returns True (1) if the argument contains at least one record.
union, doc , APIand most important deepl & keyboard shortcut