1.5 Result-set collections

1.5.1 Record class

An instance of the <record> class is a placeholder for records retrieved from the database. The record class is a collection whose elements are the columns of the records retrieved from the database. If the record object has a coercion policy (obtained through the result-set-policy), datatype coercion is performed on the elements of the record object as they are retrieved from the collection.

The elements of a record collection are ephemeral under the result-set retrieval protocol: the values for the elements of the collection can change when the next record of the result set is accessed. A result set may maintain more than one record object to improve performance.

Record collections support the forward- and backward-iteration protocols. The result of calling type-for-copy on the <record> class is <simple-object-vector>.

Applications cannot instantiate the <record> class. However, the functions returned by the forward- and backward-iteration protocol methods on the result-set classes return instances of this class.

The values in a record object have a short lifespan: they are only valid until the next fetch is performed.