Oracle LAST_VALUE function

Oracle/PLSQL LAST_VALUE function returns the last value in an ordered set of values from the analytical window. It is similar to the functions FIRST_VALUE and NTH_VALUE.

Oracle/PLSQL syntax of function LAST_VALUE

LAST_VALUE (_id)
[RESPECT NULLS | IGNORE NULLS]
OVER ([query_partition_clause_id] [order_by_clause_id])

The following syntax is also the accepted format:

LAST_VALUE (_id [RESPECT NULLS | IGNORE NULLS])
OVER ([query_partition_clause_id] [order_by_clause_id])

where:

• expression_id – The column or expression for which you want to return the last value.
• RESPECT NULLS | IGNORE NULLS – Optional. It determines whether NULL values are enabled or ignored in the analysis window. If this parameter is omitted, the default value is RESPECT NULLS, which includes NULL values.
• query_partition_clause_id – Optional. It is used to divide results into groups based on one or more expressions.
• order_by_clause_id – Optional. It is used to organize the data in each section.
• windowing_clause_id – Optional. It defines the rows in the analysis window for evaluation, and it is important that you use the correct windowing_clause, or you may get unexpected results. This can be a value such as:

The LAST_VALUE function returns the last value in an ordered set of values from the analytical window.

DDL/DML for examples

If you want to follow this guide, use the DDL to create the table and DML to fill in the data. Then try the examples in your own database!

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Example
Let’s consider some examples of Oracle LAST_VALUE functions and consider how to use LAST_VALUE function in Oracle/PLSQL.

The highest salary for all employees
Start with a simple example and use the LAST_VALUE function to return the highest salary in the employees table. In this example we do not need the query_partition_clause_id query because we evaluate the entire empls table.

In this example, we have an empls table with the following data:

To find the highest salary, enter the following SELECT:

SELECT DISTINCT LAST_VALUE(salary_id)
OVER (ORDER BY salary_id ASC)
RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)
AS "HIGH"
FROM empls;

The result you should get:

In this example, LAST_VALUE returns the highest salary value specified by LAST_VALUE (salary_id). The analysis window sorts the salary data in ascending order, as specified by ORDER BY salary_id ASC. The parameter windowing_clause_id = RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING is used to ensure that all rows are included regardless of the current row.

And since we want to get the highest salary in the table, we did not need to enable query_partition_clause_id to separate the data.

The highest salary for depart_id
Now let’s show you how to use LAST_VALUE function with query_partition_clause_id. In the next example, let’s return the highest salary for depart_id 10 and 20.

Based on the same empls table, enter the following SQL statement:

SELECT DISTINCT depart_id, LAST_VALUE(salary_id).
OVER (PARTITION BY depart_id ORDER BY salary_id ASC)
RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)
AS "HIGH"
FROM empls
WHERE depart_id in (10,20)
ORDER BY depart_id;

Here are the results you should get:

In this example, LAST_VALUE returns the highest salary value specified by LAST_VALUE (salary_id). The analysis window will divide the results into DEPART_ID and arrange the salary data in ascending order, as specified in PARTITION BY DEPART_ID ORDER BY salary_id ASC .

Lowest salary by depart_id
Now let’s show you how to use LAST_VALUE function to return the lowest salary for depart_id 10 and 20.

Again, based on the data in the empl table, enter the following SQL statement:

SELECT DISTINCT depart_id, LAST_VALUE(salary_id)
OVER (PARTITION BY depart_id ORDER BY salary_id DESC)
RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)
AS "LOW"
FROM empls
WHERE depart_id in (10,20)
ORDER BY depart_id;

Here are the results you should get:

In this example, we have changed the sort order by section as PARTITION BY DEPART_ID ORDER BY salary_id DESC and now we get the lowest salary based on DEPART_ID.

Analytic Functions in Oracle Database