In SQL, the LAST_VALUE function is used to retrieve the last value in a set of data, based on a specified ordering. This function is useful when you want to extract the most recent or current value from a column.

When combined with the BETWEEN operator, the LAST_VALUE function allows you to filter the result set based on a range of values. This can be particularly helpful in scenarios where you need to retrieve data within a specific time or numerical range.

Syntax

The syntax for using the LAST_VALUE function with the BETWEEN operator is as follows:

SELECT column_name
FROM table_name
WHERE column_name BETWEEN start_value AND end_value
AND column_name = LAST_VALUE(column_name) OVER (ORDER BY ordering_column)

In the above syntax:

• column_name refers to the column from which you want to retrieve the last value.
• table_name is the name of the table containing the data.
• start_value and end_value define the range of values to filter.
• ordering_column specifies the column used for ordering the result set.

Example

Let’s consider a scenario where you have a table named “sales” with the following columns: “date”, “product”, and “quantity”.

SELECT product, quantity
FROM sales
WHERE date BETWEEN '2022-01-01' AND '2022-12-31'
AND date = LAST_VALUE(date) OVER (ORDER BY date)

In the above example, we are retrieving the most recent quantity for each product within the specified date range. The LAST_VALUE function with the OVER clause ensures that we get the last value based on the ordering of the “date” column.

Conclusion

Using the LAST_VALUE function with the BETWEEN operator allows you to filter data based on a range, while still retrieving the last value within that range. This can be handy in various scenarios, such as tracking the latest data within a time period or extracting the most recent values within a numerical range.