This committee develops standards for the syntax and semantics of database languages. A structured type has an internal structure such as an address type that might have street, state, and postal code attributes as part of the structure. Structured types can be given specific user-defined functions and participate in type hierarchies with other structured types.
Single inheritance is supported.
With the SQL BLOB approach, an object is stored in a cell of a table or stored as a UDT in a cell of a table. It is possible to define methods that operate on the object using either approach. Each row is an instance of the type. Each attribute of the type is transformed into a column of the table. The methods associated with the type are also associated with the table.