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Name

DB.DBA.VECTOR_OF_NONNULLS_OR_NULL_AGG — Returns a vector of passed values ingoring NULL arguments.

Synopsis

vector DB.DBA.VECTOR_OF_NONNULLS_OR_NULL_AGG ( value_expression any );
 

Description

DB.DBA.VECTOR_OF_NONNULLS_OR_NULL_AGG returns a vector of passed values. Similar to DB.DBA.VECTOR_OF_NONNULLS_AGG() but returns NULL instead of an empty vector if no arguments were passed or only NULLs were passed.

Parameters

value_expression

Value of item for aggregation.

Return Types

Any. If no arguments were passed teturns NULL instead of an empty vector or only NULLs were passed.

Examples

Example 24.4. Simple Use

As the order of items in the vector repeats the order of passing individual values to the aggregate, it is possible to write, for instance: 

-- Get an ordered vector of X-es
SELECT DB.DBA.VECTOR_OF_NONNULLS_OR_NULL_AGG (subquery.X)
FROM (SELECT X FROM ... ORDER BY X) as subquery

or

SELECT DB.DBA.VECTOR_OF_NONNULLS_OR_NULL_AGG (subquery.Y)
FROM (SELECT Y FROM ... ORDER BY X) as subquery

and get vector of Y-s that are ordered by matching values of X-es.


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