# LEAD

Returns an expression evaluated at some offset after the current row.

If there is no such row returns `NULL` instead.

## 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;


```

```output

+------+----------------------------+
| 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;


```

```output

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

***

Modified at: February 16, 2023

Source: [/db/v9.1/reference/sql-reference/window-functions/lead/](https://docs.singlestore.com/db/v9.1/reference/sql-reference/window-functions/lead/)

(An index of the documentation is available at /llms.txt)