In some cases, you must specify additional parameters:
The char, nchar, varchar, nvarchar, binary, and varbinary datatypes expect a length in parentheses. If you do not supply one, Adaptive Server assumes the default length of 1 character.
The float datatype expects a precision in parentheses. If you do not supply one, Adaptive Server uses the default precision for your platform.
The numeric and decimal datatypes expect a precision and scale, in parentheses and separated by a comma. If you do not supply them, Adaptive Server uses a default precision of 18 and scale of 0.
You cannot change a user-defined datatype’s length, precision, or scale when you include it in a create table statement.
