Oracle PL/SQL/Analytical Functions/First Last

Материал из SQL эксперт
Перейти к: навигация, поиск

FIRST and LAST functions to get the first and last values in an ordered group

   <source lang="sql">

SQL> CREATE TABLE all_sales (

 2    year INTEGER,
 3    month INTEGER,
 4    prd_type_id INTEGER,
 5    emp_id INTEGER ,
 6    amount NUMBER(8, 2)
 7  );

Table created. SQL> SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,1    ,1          ,21    ,16034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,2    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,3    ,2          ,21    ,20167.83);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,4    ,2          ,21    ,25056.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,5    ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,6    ,1          ,21    ,15564.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,7    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,8    ,1          ,21    ,16434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,9    ,1          ,21    ,19654.57);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,10   ,1          ,21    ,21764.19);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,11   ,1          ,21    ,13026.73);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,12   ,2          ,21    ,10034.64);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,22    ,16634.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,21    ,26034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,2    ,1          ,21    ,12644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,3    ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,4    ,1          ,21    ,25026.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,5    ,1          ,21    ,17212.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,6    ,1          ,21    ,15564.26);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,7    ,2          ,21    ,62654.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,8    ,2          ,21    ,26434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,9    ,2          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,10   ,2          ,21    ,21264.19);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,11   ,1          ,21    ,13026.73);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,12   ,1          ,21    ,10032.64);

1 row created. SQL> SQL> select * from all_sales;

     YEAR      MONTH PRD_TYPE_ID     EMP_ID     AMOUNT

---------- ----------- ---------- ----------
     2006          1           1         21   16034.84
     2006          2           1         21   15644.65
     2006          3           2         21   20167.83
     2006          4           2         21   25056.45
     2006          5           2         21
     2006          6           1         21   15564.66
     2006          7           1         21   15644.65
     2006          8           1         21   16434.82
     2006          9           1         21   19654.57
     2006         10           1         21   21764.19
     2006         11           1         21   13026.73
     2006         12           2         21   10034.64
     2005          1           2         22   16634.84
     2005          1           2         21   26034.84
     2005          2           1         21   12644.65
     2005          3           1         21
     2005          4           1         21   25026.45
     2005          5           1         21   17212.66
     2005          6           1         21   15564.26
     2005          7           2         21   62654.82
     2005          8           2         21   26434.82
     2005          9           2         21   15644.65
     2005         10           2         21   21264.19
     2005         11           1         21   13026.73
     2005         12           1         21   10032.64

25 rows selected. SQL> SQL> --FIRST and LAST functions to get the first and last values in an ordered group. SQL> SQL> --You can use FIRST and LAST with the following functions: MIN(), MAX(), COUNT(), SUM(), AVG(), STDDEV(), and VARIANCE(). SQL> SQL> SELECT

 2   MIN(month) KEEP (DENSE_RANK FIRST ORDER BY SUM(amount))
 3    AS highest_sales_month,
 4   MIN(month) KEEP (DENSE_RANK LAST ORDER BY SUM(amount))
 5    AS lowest_sales_month
 6  FROM all_sales
 7  GROUP BY month
 8  ORDER BY month;

HIGHEST_SALES_MONTH LOWEST_SALES_MONTH


------------------
                 5                  7

SQL> SQL> SQL> SQL> drop table all_sales; Table dropped. SQL> SQL>

      </source>