CARDINALITY

Syntax

Description of the illustration cardinality.gif

Purpose

CARDINALITY returns the number of elements in a nested table. The return type is NUMBER. If the nested table is empty, or is a null collection, then CARDINALITY returns NULL.

Examples

The following example shows the number of elements in the nested table column ad_textdocs_ntab of the sample table pm.print_media:

SELECT product_id, CARDINALITY(ad_textdocs_ntab) cardinality
  FROM print_media
  ORDER BY product_id;

PRODUCT_ID CARDINALITY
---------- -----------
      2056           3
      2268           3
      3060           3
      3106           3