I'm stuck on an update query.
Please help understand this error
Schema should contain at least one unique index.
in this query
code
UPDATE [Table]
SET [Zip3_int] = cast(StringSubstringLen(cast([GeoPostalCode] as varchar),0,3) as int32)
tables are not writable (includes updates, of course) if they don't have an index.
See http://manifold.net/doc/radian/index.htm#editing_tables.htm and http://manifold.net/doc/radian/index.htm#adding_an_index_to_a_table.htm and similar topics.