Important

Self-managed SingleStore will soon transition from version 9.1 RC to version 10. This new semantic versioning scheme will provide SingleStore with finer control over engine and feature releases that were not possible with the current versioning scheme.

In the interim, SingleStore 9.1 RC can be used to preview, evaluate, and provide feedback on the new and upcoming features in SingleStore 10 prior to its general availability. Ahead of this transition, SingleStore 9.0 is recommended for production workloads, which can later be upgraded to SingleStore 10.

LAST_VALUE

Syntax

LAST_VALUE ( expression ) OVER (
    [PARTITION BY (col | expr), ...]
    [ORDER BY (col | expr), ...]
    [frame_clause]
)

Arguments

expression: any expression. This may be a column name, the result of another function, or a math operation.

Return Type

The result type of expression

Examples

SQL

CREATE TABLE lv_example (a INT, b INT);

INSERT INTO lv_example VALUES(1, 2), (2, 2), (3, 3), (4, 3);

SQL

CREATE TABLE tick_table(TIMESTAMP DATETIME(6), symbol VARCHAR(5), comp_name VARCHAR (30), price NUMERIC(18,4));

INSERT INTO tick_table VALUES('2022-11-18 10:55:36.000000','STC','SomeTechCo', 100.00),
('2022-11-18 10:55:37.000000','STC','SomeTechCo', 102.00),
('2022-11-18 10:55:42.000000', 'STC', 'SomeTechCo', 105.00),
('2022-11-18 10:55:48.000000', 'STC', 'SomeTechCo', 101.00),
('2022-11-18 10:56:03.000000', 'STC', 'SomeTechCo', 99.00),
('2022-11-18 10:55:42.000000', 'AME', 'ACME', 198.00),
('2022-11-18 10:55:50.000000', 'AME', 'ACME', 208.00),
('2022-11-18 10:55:52.000000', 'AME', 'ACME', 210.00),
('2022-11-18 10:55:55.000000', 'AME', 'ACME', 211.00),
('2022-11-18 10:55:52.000000', 'OCO', 'OnCallCo', 21.00),
('2022-11-18 10:55:55.000000', 'OCO', 'OnCallCo', 22.00),
('2022-11-18 10:55:57.000000', 'OCO', 'OnCallCo', 21.00),
('2022-11-18 10:56:00.000000', 'OCO', 'OnCallCo', 23.00),
('2022-11-18 10:56:03.000000', 'OCO', 'OnCallCo', 24.00);

Window Function

SQL

SELECT a, LAST_VALUE(a) OVER(ORDER BY (a)) FROM lv_example;

+------+----------------------------------+
| a    | LAST_VALUE(a) OVER(ORDER BY (a)) |
+------+----------------------------------+
|    1 |                                1 |
|    2 |                                2 |
|    3 |                                3 |
|    4 |                                4 |
+------+----------------------------------+

Window Frame Clause

SQL

SELECT a, LAST_VALUE(a) OVER(ORDER BY (a) ROWS between  CURRENT ROW and UNBOUNDED FOLLOWING) AS Result FROM lv_exa
mple;

+------+--------+
| a    | Result |
+------+--------+
|    1 |      4 |
|    2 |      4 |
|    3 |      4 |
|    4 |      4 |
+------+--------+

SQL

SELECT TIMESTAMP, symbol, price, LAST_VALUE(price) OVER (
PARTITION BY symbol) AS Result FROM tick_table GROUP BY TIMESTAMP;

+----------------------------+--------+----------+----------+
| TIMESTAMP                  | symbol | price    | Result   |
+----------------------------+--------+----------+----------+
| 2022-11-18 10:55:52.000000 | AME    | 210.0000 | 208.0000 |
| 2022-11-18 10:55:42.000000 | AME    | 198.0000 | 208.0000 |
| 2022-11-18 10:55:50.000000 | AME    | 208.0000 | 208.0000 |
| 2022-11-18 10:55:36.000000 | STC    | 100.0000 | 101.0000 |
| 2022-11-18 10:56:03.000000 | STC    |  99.0000 | 101.0000 |
| 2022-11-18 10:55:37.000000 | STC    | 102.0000 | 101.0000 |
| 2022-11-18 10:55:48.000000 | STC    | 101.0000 | 101.0000 |
| 2022-11-18 10:56:00.000000 | OCO    |  23.0000 |  21.0000 |
| 2022-11-18 10:55:55.000000 | OCO    |  22.0000 |  21.0000 |
| 2022-11-18 10:55:57.000000 | OCO    |  21.0000 |  21.0000 |
+----------------------------+--------+----------+----------+