Lag
Returns the value from a previous row at a specified offset before the current row within a partition.
Category: window
Syntax:
Lag([column], offset)
Returns: Same as input type
Context Filtering: ✓ Yes
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
column |
column |
✓ Yes | The column to retrieve the previous value from |
offset |
integer |
✗ No | The number of rows before the current row to retrieve the value from. Defaults to 1. |
Validation
- Minimum parameters: 1
- Maximum parameters: 2
Examples
Lag([Sales])
Returns the sales value from the previous row (1 row back).
Lag([Price], 3)
Returns the price value from 3 rows before the current row.
Lag([Revenue], 7)
Returns the revenue from 7 days ago, useful for week-over-week comparisons.