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
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.
Parameters
x
— Column name.offset
— Offset to apply. (U)Int*. (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:
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);
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:
┌───────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 │
└────────────┴────────┴────────────────────┴───────┴────────────────┘