The DROP TYPE statement removes a user-defined type (UDT) that was created using a CREATE TYPE statement.
DROP TYPE [ schemaName. ] SQL92Identifier RESTRICT
The type name is composed of an optional schemaName and a SQL92Identifier. If a schemaName is not provided, the current schema is the default schema. If a qualified type name is specified, the schema name cannot begin with SYS.
The RESTRICT keyword is required. CASCADE semantics are not supported. That is, Derby will not track down and drop orphaned objects.
Dropping a UDT implicitly drops all USAGE privileges that reference it.
You cannot drop a type if it would make another SQL object unusable. This includes the following restrictions:
DROP TYPE price RESTRICT;