Oracle PL/SQL Tutorial/Linear Regression Functions/STDDEV
STDDEV([DISTINCT | ALL] value) [OVER (analytic_clause)] returns the standard deviation value
<source lang="sql">
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); 1 row created. SQL> insert into myTable(ID, value)values (2,2.11); 1 row created. SQL> insert into myTable(ID, value)values (3,3.44); 1 row created. SQL> insert into myTable(ID, value)values (4,-4.21); 1 row created. SQL> insert into myTable(ID, value)values (5,10); 1 row created. SQL> insert into myTable(ID, value)values (6,3); 1 row created. SQL> insert into myTable(ID, value)values (7,-5.88); 1 row created. SQL> insert into myTable(ID, value)values (8,123.45); 1 row created. SQL> insert into myTable(ID, value)values (9,98.23); 1 row created. SQL> insert into myTable(ID, value)values (10,938.23); 1 row created. SQL> insert into myTable(ID, value)values (11,984.23); 1 row created. SQL> insert into myTable(ID, value)values (12,198.23); 1 row created. SQL> insert into myTable(ID, value)values (13,928.87); 1 row created. SQL> insert into myTable(ID, value)values (14,25.37); 1 row created. SQL> insert into myTable(ID, value)values (15,918.3); 1 row created. SQL> insert into myTable(ID, value)values (16,9.23); 1 row created. SQL> insert into myTable(ID, value)values (17,8.23); 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
10 938.23
11 984.23
ID VALUE
----------
12 198.23
13 928.87
14 25.37
15 918.3
16 9.23
17 8.23
17 rows selected. SQL> SQL> SQL> SELECT STDDEV(value) FROM myTable; STDDEV(VALUE)
399.834568
SQL> SQL> SQL> SQL> -- clean the table SQL> drop table myTable
2 /
Table dropped. SQL> SQL> SQL></source>
