Question

How to know if all the cells have the same value in some column (title changed)

I want to have a bit scalar value that tells me if all the values in a column equal something:

DECLARE @bit bit
SELECT @bit = TRUEFORALL(Name IS NOT NULL) FROM Contact

UPDATE

I now realized that I actually don’t need the TrueForAll, what I do need is to make sure, that all values in a column are equal, for example, I want to know whether all Group.Items have the same price.

Answer 1

For your updated requirement something like this would appear to do what you want:

DECLARE @IsSameGroup bit
SELECT @IsSameGroup = CASE WHEN COUNT(*) > 1 THEN 0 ELSE 1 END
FROM (SELECT Name FROM Contact GROUP BY Name) groups

When the count is greater the 1 you have two different names (or prices depending on what you group on)