MS-SQL - select using HAVING count(field-name) > 1

[UHsoccer]

I am trying to identify duplicate entries in a data base table, using the following

SELECT *
FROM MyTable
WHERE (categoryId = 6) AND (categoryVal = '45')
HAVING (COUNT(CompanyId) > 1)

It fails referencing field number 1 (rKey) which is an automatically generated ID field.
Any help appreciated

 

[surflex]

Instead of selecting all columns(*) name your columns and leave out the identifier column. If you have to have it then try converting it to a varchar in the select statement.