LAST_VALUE

Warning

SingleStore 9.0 gives you the opportunity to preview, evaluate, and provide feedback on new and upcoming features prior to their general availability. In the interim, SingleStore 8.9 is recommended for production workloads, which can later be upgraded to SingleStore 9.0.

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) FROM lv_example;

+------+---------------------------------------------------+
| a    | LAST_VALUE(a) OVER(ORDER BY (a)                   |
|      | ROWS between CURRENT ROW and UNBOUNDED FOLLOWING) |
+------+---------------------------------------------------+
|    1 |                                                 4 |
|    2 |                                                 4 |
|    3 |                                                 4 |
|    4 |                                                 4 |
+------+---------------------------------------------------+

SQL

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

+----------------------------+--------+----------+------------------------+
| TIMESTAMP                  | symbol | price    | LAST_VALUE(price) OVER |
|                            |        |          | (PARTITION BY symbol)  |
+----------------------------+--------+----------+------------------------+
| 2022-11-18 10:55:55.000000 | AME    | 211.0000 |               210.0000 |
| 2022-11-18 10:55:50.000000 | AME    | 208.0000 |               210.0000 |
| 2022-11-18 10:55:42.000000 | AME    | 198.0000 |               210.0000 |
| 2022-11-18 10:55:52.000000 | AME    | 210.0000 |               210.0000 |
| 2022-11-18 10:55:57.000000 | OCO    |  21.0000 |                23.0000 |
| 2022-11-18 10:56:00.000000 | OCO    |  23.0000 |                23.0000 |
| 2022-11-18 10:55:36.000000 | STC    | 100.0000 |                99.0000 |
| 2022-11-18 10:55:37.000000 | STC    | 102.0000 |                99.0000 |
| 2022-11-18 10:55:48.000000 | STC    | 101.0000 |                99.0000 |
| 2022-11-18 10:56:03.000000 | STC    |  99.0000 |                99.0000 |
+----------------------------+--------+----------+------------------------+