In SQL, the LAST_VALUE function is used to retrieve the last value in a specified column, based on a specified order. It is commonly used in scenarios where you want to find the most recent value in a column.

However, there may be cases where you want to apply the LAST_VALUE function on a distinct set of values from a column. In such cases, you can use the DISTINCT clause along with the LAST_VALUE function to achieve the desired result.

Here’s an example that demonstrates how to use the LAST_VALUE function with the DISTINCT clause in SQL:

SELECT DISTINCT column_name,
       LAST_VALUE(column_name) OVER (PARTITION BY distinct_column ORDER BY order_column) AS last_value
FROM table_name;

In this example, column_name represents the column for which you want to find the last value. distinct_column specifies the column based on which you want to select distinct values. order_column defines the column that determines the order in which the LAST_VALUE function operates.

By using the DISTINCT clause, the query will return only the distinct values from the column_name column. The LAST_VALUE function will then be applied to these distinct values, giving you the last value for each distinct value in the specified column.

It’s worth noting that the DISTINCT clause is applied before the LAST_VALUE function, ensuring that only unique values are considered when computing the last value.

Using the LAST_VALUE function with the DISTINCT clause can be helpful in various scenarios, such as finding the most recent transaction for each distinct customer or retrieving the latest measurement for each distinct device in a dataset.

#sql #lastvalue