Visual Database Tools
Column '<1s>' in table '<0s>' participates in index '<2s>'. Columns with a datatype of '<3s>' cannot participate in indexes or primary keys.
You have attempted to change the datatype of a column that is part of an index or a primary key. Indexes and primary keys cannot be created for columns with datatypes such as TEXT or IMAGE. To change the datatype, first remove the index or primary key.
For more information see Indexes, Creating a Unique Index, and Defining a Primary Key.