mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-15 20:24:07 +00:00
79 lines
2.9 KiB
Markdown
79 lines
2.9 KiB
Markdown
---
|
|
slug: /en/sql-reference/window-functions/lagInFrame
|
|
sidebar_label: lagInFrame
|
|
sidebar_position: 9
|
|
---
|
|
|
|
# lagInFrame
|
|
|
|
Returns a value evaluated at the row that is at a specified physical offset row before the current row within the ordered frame.
|
|
|
|
**Syntax**
|
|
|
|
```sql
|
|
lagInFrame(x[, offset[, default]])
|
|
OVER ([[PARTITION BY grouping_column] [ORDER BY sorting_column]
|
|
[ROWS or RANGE expression_to_bound_rows_withing_the_group]] | [window_name])
|
|
FROM table_name
|
|
WINDOW window_name as ([[PARTITION BY grouping_column] [ORDER BY sorting_column])
|
|
```
|
|
|
|
For more detail on window function syntax see: [Window Functions - Syntax](./index.md/#syntax).
|
|
|
|
**Parameters**
|
|
- `x` — Column name.
|
|
- `offset` — Offset to apply. [(U)Int*](../data-types/int-uint.md). (Optional - `1` by default).
|
|
- `default` — Value to return if calculated row exceeds the boundaries of the window frame. (Optional - default value of column type when omitted).
|
|
|
|
**Returned value**
|
|
|
|
- Value evaluated at the row that is at a specified physical offset before the current row within the ordered frame.
|
|
|
|
**Example**
|
|
|
|
This example looks at historical data for a specific stock and uses the `lagInFrame` function to calculate a day-to-day delta and percentage change in the closing price of the stock.
|
|
|
|
Query:
|
|
|
|
```sql
|
|
CREATE TABLE stock_prices
|
|
(
|
|
`date` Date,
|
|
`open` Float32, -- opening price
|
|
`high` Float32, -- daily high
|
|
`low` Float32, -- daily low
|
|
`close` Float32, -- closing price
|
|
`volume` UInt32 -- trade volume
|
|
)
|
|
Engine = Memory;
|
|
|
|
INSERT INTO stock_prices FORMAT Values
|
|
('2024-06-03', 113.62, 115.00, 112.00, 115.00, 438392000),
|
|
('2024-06-04', 115.72, 116.60, 114.04, 116.44, 403324000),
|
|
('2024-06-05', 118.37, 122.45, 117.47, 122.44, 528402000),
|
|
('2024-06-06', 124.05, 125.59, 118.32, 121.00, 664696000),
|
|
('2024-06-07', 119.77, 121.69, 118.02, 120.89, 412386000);
|
|
```
|
|
|
|
```sql
|
|
SELECT
|
|
date,
|
|
close,
|
|
lagInFrame(close, 1, close) OVER (ORDER BY date ASC) AS previous_day_close,
|
|
COALESCE(ROUND(close - previous_day_close, 2)) AS delta,
|
|
COALESCE(ROUND((delta / previous_day_close) * 100, 2)) AS percent_change
|
|
FROM stock_prices
|
|
ORDER BY date DESC;
|
|
```
|
|
|
|
Result:
|
|
|
|
```response
|
|
┌───────date─┬──close─┬─previous_day_close─┬─delta─┬─percent_change─┐
|
|
1. │ 2024-06-07 │ 120.89 │ 121 │ -0.11 │ -0.09 │
|
|
2. │ 2024-06-06 │ 121 │ 122.44 │ -1.44 │ -1.18 │
|
|
3. │ 2024-06-05 │ 122.44 │ 116.44 │ 6 │ 5.15 │
|
|
4. │ 2024-06-04 │ 116.44 │ 115 │ 1.44 │ 1.25 │
|
|
5. │ 2024-06-03 │ 115 │ 115 │ 0 │ 0 │
|
|
└────────────┴────────┴────────────────────┴───────┴────────────────┘
|
|
``` |