Important

The SingleStore 9.1 release candidate (RC) is available now. It will be promoted to general availability (GA) soon and at that time it will be renamed to SingleStore 10.

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, while SingleStore 9.0 is recommended for production workloads.

LEAD

Syntax

LEAD ( expression [, offset]) OVER (
    [PARTITION BY (col | expr), ...]
    [ORDER BY (col | expr), ...]
)

Arguments

expression: any expression. This may be a column name, the result of another function, or a math operation
offset: A constant integer that specifies the number of rows after the current row to evaluate the expression. Defaults to 1 if not specified

Return Type

The result of expression

Examples

SQL

CREATE TABLE lead_example (a int, b int);

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

SQL

SELECT a, LEAD(a) OVER(ORDER BY (a)) FROM lead_example;

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

SQL

SELECT a, LEAD(a,2) OVER(ORDER BY (a)) FROM lead_example;

+------+------------------------------+
| a    | LEAD(a,2) OVER(ORDER BY (a)) |
+------+------------------------------+
|    1 |                            3 |
|    2 |                            4 |
|    3 |                         NULL |
|    4 |                         NULL |
+------+------------------------------+