CARDINALITY Function (IDS)

The CARDINALITY function returns the number of elements in a collection column (SET, MULTISET, LIST).

CARDINALITY Function:
 
|--CARDINALITY--(--+-collection_col-+--)------------------------|
                   '-collection_var-'

Element	Description	Restrictions	Syntax
collection_col	An existing collection column	Must be declared as a collection data type	Identifier, p. Identifier
collection_var	Host or program collection variable	Must be declared as a collection data type	Language specific

Suppose that the set_col SET column contains the following value:

{3, 7, 9, 16, 0}

The following SELECT statement returns 5 as the number of elements in the set_col column:

SELECT CARDINALITY(set_col)
   FROM table1

If the collection contains duplicate elements, CARDINALITY counts each individual element.