LAST_VALUE
Returns an expression evaluated at the last row of the window frame.
If there are no rows in the frame, returns NULL.
For an overview of window functions in SingleStoreDB, see Window Functions Guide.
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
CREATE TABLE lv_example (a INT, b INT); INSERT INTO lv_example VALUES(1, 2), (2, 2), (3, 3), (4, 3);
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
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
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 | +------+---------------------------------------------------+
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 | +----------------------------+--------+----------+------------------------+