COVAR_SAMP Function in oracle sql

The COVAR_SAMP Function in Oracle SQL / PLSQL is used to calculate the sample covariance of a set of numbers in pairs.

Syntax for the using the COVAR_SAMP Function in Oracle SQL / PLSQL is:

SELECT COVAR_SAMP(expression_1, expression_2)
FROM table_name;

• expression_1 and expression_2 are numeric expressions
• The COVAR_SAMP function in Oracle SQL / PLSQL will eliminate all the pairs where expression_1 and expression_2 are having NULL values.

Example:

Using COVAR_SAMP Function in Oracle SQL / PLSQL SELECT statement:

Suppose we have a table named ‘employee’ as shown below:

Employee_ID	Employee_Name	Salary	Department	Commission
101	Emp A	10000	Sales
102	Emp B	20000	IT	20
103	Emp C	28000	IT	20
104	Emp D	30000	Support
105	Emp E	32000	Sales	10
106	Emp F	40000	Sales	10
107	Emp G	12000	Sales	10
108	Emp H	12000	Support

If we write our COVAR_SAMP Function query as:

SELECT COVAR_SAMP(salary, commission)
FROM employee;

We will get ‘-7500’ as output