lastval

lastval — aggregate function to return the last value from a specified column.

SYNOPSIS

lastval (expr)

DESCRIPTION

This function returns the last non-null value, if any, 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 last value is of the same type as the specified column.

If the query returns no rows, the aggregate returns null.

EXAMPLE

This example shows a simple use of the lastval() function.

  1. In LiveView Desktop connected to a server running the Hello LiveView sample, select the ItemsSales table from the Tables pane of the LiveView Tables view.

  2. In the Select field, enter: 

    lastval(Item) as Last

  3. Make sure the Query field is empty.

  4. Click Open Query.

The query results open in a grid view. The value continuously updates as new values arrive.

SEE ALSO

This LiveView aggregate function is based on the lastval aggregate function in the StreamBase expression language.