Oracle PL/SQL Tutorial/Numerical Math Functions/POWER — различия между версиями
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Текущая версия на 10:08, 26 мая 2010
Содержание
POWER(2, 1)
SQL> select POWER(2, 1) from dual;
POWER(2,1)
----------
2
POWER(2, 3)
SQL> select POWER(2, 3) from dual;
POWER(2,3)
----------
8
POWER(x, y) gets the result of x raised to the power y.
The following example uses POWER() to display 2 raised to the power 1 and 3, respectively:
SQL> SELECT POWER(2, 1), POWER(2, 3) FROM dual;
POWER(2,1) POWER(2,3)
---------- ----------
2 8
SQL>
select power(2,3), power(-2,3)
SQL>
SQL>
SQL>
SQL> select power(2,3), power(-2,3)
2 from dual;
POWER(2,3) POWER(-2,3)
---------- -----------
8 -8
SQL>
Using the POWER function
The POWER function requires two arguments.
The first argument is the value that you would like raised to some exponential power.
The second argument is the power (exponent) that you would like the number raised to.
SQL>
SQL>
SQL> -- create demo table
SQL> create table myTable(
2 id NUMBER(2),
3 value NUMBER(6,2)
4 )
5 /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into myTable(ID, value)values (1,9)
2 /
1 row created.
SQL> insert into myTable(ID, value)values (2,2.11)
2 /
1 row created.
SQL> insert into myTable(ID, value)values (3,3.44)
2 /
1 row created.
SQL> insert into myTable(ID, value)values (4,-4.21)
2 /
1 row created.
SQL> insert into myTable(ID, value)values (5,10)
2 /
1 row created.
SQL> insert into myTable(ID, value)values (6,3)
2 /
1 row created.
SQL> insert into myTable(ID, value)values (7,-5.88)
2 /
1 row created.
SQL> insert into myTable(ID, value)values (8,123.45)
2 /
1 row created.
SQL> insert into myTable(ID, value)values (9,98.23)
2 /
1 row created.
SQL>
SQL> select * from myTable
2 /
ID VALUE
---------- ----------
1 9
2 2.11
3 3.44
4 -4.21
5 10
6 3
7 -5.88
8 123.45
9 98.23
9 rows selected.
SQL>
SQL> select power(value, 2) from myTable
2 /
POWER(VALUE,2)
--------------
81
4.4521
11.8336
17.7241
100
9
34.5744
15239.9025
9649.1329
9 rows selected.
SQL>
SQL> select power(value, 3) from myTable
2 /
POWER(VALUE,3)
--------------
729
9.393931
40.707584
-74.618461
1000
27
-203.29747
1881365.96
947834.325
9 rows selected.
SQL>
SQL>
SQL> -- clean the table
SQL> drop table myTable
2 /
Table dropped.
SQL>