Oracle SQL - Function STDDEV function

Introduction

STDDEV function returns the standard deviation value.

The general format for this function is:

STDDEV([DISTINCT | ALL] value) [OVER (analytic_clause)] 

Demo

SQL>
SQL>--  w ww. j  av a 2  s.  co  m
SQL> SELECT STDDEV(y) FROM my_table;

STDDEV(Y)
---------
 00274.65

SQL>

Given the following table.

Demo

SQL>
SQL> drop table my_table;

Table dropped.--   w w  w  .  j a  v a  2 s .  c  o  m

SQL> create table my_table(
  2  x      NUMBER(4)  primary key,
  3  y      NUMBER(4)  not null);
SQL>
SQL> insert into my_table values(1,2);
SQL> insert into my_table values(2,4);
SQL> insert into my_table values(3,6);
SQL> insert into my_table values(4,9);
SQL> insert into my_table values(5,13);
SQL> insert into my_table values(6,16);
SQL> insert into my_table values(7,20);
SQL> insert into my_table values(8,27);
SQL> insert into my_table values(9,32);
SQL> insert into my_table values(10,47);
SQL> insert into my_table values(11,53);
SQL> insert into my_table values(12,60);
SQL> insert into my_table values(13,76);
SQL> insert into my_table values(14,100);
SQL> insert into my_table values(15,130);
SQL> insert into my_table values(16,189);
SQL> insert into my_table values(17,300);
SQL> insert into my_table values(18,789);
SQL> insert into my_table values(19,1000);
SQL>