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SQL programmingYou can use the HCL OneDB™ implementation of the SQL language to develop applications for HCL OneDB™ database servers.
Guide to SQL: SyntaxThe HCL OneDB™ Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the HCL OneDB™ dialect of the SQL language.
Data types and expressionsThese topics describe the data types and expressions that HCL OneDB™supports.
Expression
Function Expressions
CARDINALITY FunctionThe CARDINALITY function returns the number of elements in a collection column (SET, MULTISET, LIST).

CARDINALITY Function

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

The CARDINALITY function has the following syntax.


Element	Description	Restrictions	Syntax
collection_col	An existing collection column	Must be declared as a collection data type	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.