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SQL Anywhere 12.0.0 (Français) » SQL Anywhere Server - SQL Usage » Querying and modifying data » OLAP support » Window functions in SQL Anywhere » Basic aggregate functions


FIRST_VALUE and LAST_VALUE function examples

The FIRST_VALUE and LAST_VALUE functions return values from the first and last rows of a window. This allows a query to access values from multiple rows at once, without the need for a self-join.

These two functions are different from the other window aggregate functions because they must be used with a window. Also, unlike the other window aggregate functions, these functions allow the IGNORE NULLS clause. If IGNORE NULLS is specified, the first or last non-NULL value of the desired expression is returned. Otherwise, the first or last value is returned.

 Example 1: First entry in a group
 Example 2: Percentage of highest sales
 Example 3: Populating NULL values making data more dense
 See also