Question

Is there a built-in, or workaround technique, to determine if a character “IsAlpha“?

---

i see a lot of suggestions that revolve around

IF PATINDEX('[a-zA-Z]', @c) > 0
BEGIN
   --It is alpha
END

Except that neglects alpha characters that are not in the given range A-Z.

Answer 1

Collation controls how accents and diacritics are evaluated, such as whether or not S equals Š.

Note the results for the following… the first SELECT returns 2 matches, the second only returns 1 match:

DECLARE @testTable TABLE (testValue nvarchar(50))

insert into @testTable (testValue) values ('Š')
insert into @testTable (testValue) values ('S')
insert into @testTable (testValue) values ('4')

SELECT 'IsAlpha', testValue 
FROM @testTable 
WHERE PATINDEX('[a-zA-Z]', testValue COLLATE Latin1_General_CS_AS) > 0 

SELECT 'IsAlpha', testValue 
FROM @testTable 
WHERE PATINDEX('[a-zA-Z]', testValue COLLATE LATIN1_GENERAL_BIN) > 0 

You can find a list of collations within SQL Server 2008 and a brief descripition here.