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Oracle® Database SQL Language Reference
11g Release 1 (11.1)

Part Number B28286-01
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Description of first.gif follows
Description of the illustration first.gif

See Also:

"Analytic Functions" for information on syntax, semantics, and restrictions of the ORDER BY clause and OVER clause


FIRST and LAST are very similar functions. Both are aggregate and analytic functions that operate on a set of values from a set of rows that rank as the FIRST or LAST with respect to a given sorting specification. If only one row ranks as FIRST or LAST, then the aggregate operates on the set with only one element.

This function takes as an argument any numeric datatype or any nonnumeric datatype that can be implicitly converted to a numeric datatype. The function returns the same datatype as the numeric datatype of the argument.

When you need a value from the first or last row of a sorted group, but the needed value is not the sort key, the FIRST and LAST functions eliminate the need for self-joins or views and enable better performance.

You can use the FIRST and LAST functions as analytic functions by specifying the OVER clause. The query_partitioning_clause is the only part of the OVER clause valid with these functions.

See Also:

Table 2-10, "Implicit Type Conversion Matrix" for more information on implicit conversion and LAST

Aggregate Example

The following example returns, within each department of the sample table hr.employees, the minimum salary among the employees who make the lowest commission and the maximum salary among the employees who make the highest commission:

SELECT department_id,
MIN(salary) KEEP (DENSE_RANK FIRST ORDER BY commission_pct) "Worst",
MAX(salary) KEEP (DENSE_RANK LAST ORDER BY commission_pct) "Best"
   FROM employees
   GROUP BY department_id
   ORDER BY department_id, "Worst", "Best";

DEPARTMENT_ID      Worst       Best
------------- ---------- ----------
           10       4400       4400
           20       6000      13000
           30       2500      11000
           40       6500       6500
           50       2100       8200
           60       4200       9000
           70      10000      10000
           80       6100      14000
           90      17000      24000
          100       6900      12000
          110       8300      12000
                    7000       7000

Analytic Example

The next example makes the same calculation as the previous example but returns the result for each employee within the department:

SELECT last_name, department_id, salary,
   MIN(salary) KEEP (DENSE_RANK FIRST ORDER BY commission_pct)
      OVER (PARTITION BY department_id) "Worst",
   MAX(salary) KEEP (DENSE_RANK LAST ORDER BY commission_pct)
      OVER (PARTITION BY department_id) "Best"
    FROM employees
    ORDER BY department_id, salary;

LAST_NAME           DEPARTMENT_ID     SALARY      Worst       Best
------------------- ------------- ---------- ---------- ----------
Whalen                         10       4400       4400       4400
Fay                            20       6000       6000      13000
Hartstein                      20      13000       6000      13000
. . .
Gietz                         110       8300       8300      12000
Higgins                       110      12000       8300      12000
Grant                                   7000       7000       7000