Routines: Row functions

A row function is a function, which can only be used with user-defined structured types, that for each set of one or more scalar parameters returns a single row.

Row functions can only be used as a transform function mapping attributes of a structured type into built-in data type values in a row. Row functions cannot be used in a standalone manner or within SQL statements outside of the context of abstract data types.

Features

• Allows you to map structured type attributes to a row of built-in data type values.

Limitations

• Cannot be used in a standalone manner or in SQL statements outside of the context of user-defined structured types.

Common uses

To make structured type attributes accessible in queries or operations. For example, consider a user-defined structured data type named, 'manager' that extends another structured type person and that has a combination of person attributes and manager specific attributes. If you wanted to refer to these values in a query, you would create a row function to translate the attribute values into a row of values that can be referenced.

Supported implementations

• SQL implementation