# Other Functions

## ROW\_NUMBER

`ROW_NUMBER() OVER()`

**Description:**

Assign a sequential integer to each row as a row number. The row number starts from 1.

**Example**

```
ROW_NUMBER() OVER()
```

Result:

| row\_number |
| ----------- |
| 1           |
| 2           |
| 3           |

## LAG

`LAG(column1, [n_lags]) OVER(ORDER BY column2)`

**Description**

Move each value in column1 forward to the next row. The table will be ordered by column2 first before values are moved. If n\_lags is specified, each value is shifted to the next n\_lags rows. The first n\_lags values will be NULL.

**Example**

```
price_lag = LAG(price) OVER(ORDER BY date)
```

Result:

| date  | price | price\_lag |
| ----- | ----- | ---------- |
| 12-11 | 30    | NULL       |
| 12-12 | 32    | 30         |
| 12-13 | 28    | 32         |