Issue creating local Attributes

I was unable to create new local attributes even after running the AddColumns wt.part.WTPart String=1 query in the Windchill shell. Although the attribute columns were successfully added to the wt.part.WTPart table and the corresponding columns are visible in the database, the new local attributes are not being created still getting same old error “ A string attributes cannot be created because database columns of the following datatype are not available