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 SingleStore, 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 |
+----------------------------+--------+----------+------------------------+

Last modified: February 16, 2023

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Verification instructions

Note: You must install cosign to verify the authenticity of the SingleStore file.

Use the following steps to verify the authenticity of singlestoredb-server, singlestoredb-toolbox, singlestoredb-studio, and singlestore-client SingleStore files that have been downloaded.

You may perform the following steps on any computer that can run cosign, such as the main deployment host of the cluster.

  1. (Optional) Run the following command to view the associated signature files.

    curl undefined
  2. Download the signature file from the SingleStore release server.

    • Option 1: Click the Download Signature button next to the SingleStore file.

    • Option 2: Copy and paste the following URL into the address bar of your browser and save the signature file.

    • Option 3: Run the following command to download the signature file.

      curl -O undefined
  3. After the signature file has been downloaded, run the following command to verify the authenticity of the SingleStore file.

    echo -n undefined |
    cosign verify-blob --certificate-oidc-issuer https://oidc.eks.us-east-1.amazonaws.com/id/CCDCDBA1379A5596AB5B2E46DCA385BC \
    --certificate-identity https://kubernetes.io/namespaces/freya-production/serviceaccounts/job-worker \
    --bundle undefined \
    --new-bundle-format -
    Verified OK