MS SQL verifies if the string contains uppercase and lowercase letters

Last night there was a small function, that is, in MS SQL Server, check whether the string contains uppercase and lowercase letters. The complexity of the string is usually applied.

DECLARE @s NVARCHAR( +)=N'Sdffggryjhhtyuj'IF LOWER(@s) COLLATE Latin1_General_CS_AS<> @s  and UPPER(@s) COLLATE Latin1_General_CS_AS<> @s    PRINT 'T'ELSE    PRINT 'F'

Source Code

Real-time Operation demo, empty string, all lowercase, all uppercase, the size of mixed-write conditions:

MS SQL verifies if the string contains uppercase and lowercase letters