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last aggregate function

  • Άρθρο

Applies to: check marked yes Databricks SQL check marked yes Databricks Runtime

Returns the last value of expr for the group of rows. The function is a synonym for last_value aggregate function.

Syntax

last(expr [, ignoreNull] ) [FILTER ( WHERE cond ) ] [ IGNORE NULLS | RESPECT NULLS ]

This function can also be invoked as a window function using the OVER clause.

Arguments

  • expr: An expression of any type.
  • ignoreNull: An optional BOOLEAN literal that defaults to false.
  • cond: An optional boolean expression filtering the rows used for aggregation.
  • IGNORE NULLS or RESPECT NULLS: When IGNORE NULLS is used or ignoreNull is true any expr value that is NULL is ignored. The default is RESPECT NULLS.

Returns

The result type matches expr.

This function is non-deterministic.

Examples

> SELECT last(col) FROM VALUES (10), (5), (20) AS tab(col);
 20

> SELECT last(col) FROM VALUES (10), (5), (NULL) AS tab(col);
 NULL

> SELECT last(col, true) FROM VALUES (10), (5), (NULL) AS tab(col);
 5

> SELECT last(col) IGNORE NULLS FROM VALUES (10), (5), (NULL) AS tab(col);
 5

> SELECT last(col) FILTER (WHERE col > 5) FROM VALUES (5), (20) AS tab(col);
 20