firstval
firstval — aggregate function to return the first value from a specified column.
DESCRIPTION
This function returns the first value in the range of values returned by its query predicate.
Expression expr
must contain the name of a
column in a LiveView table. The returned first value is of the same type as the
specified column.
If the query returns no rows, the aggregate returns null
when group-by is not specified, and no rows when a group-by is specified.
SEE ALSO
This LiveView aggregate function is based on the firstval aggregate function in the StreamBase expression language.