JetSQL » Functions » VAR
- Syntax:
-
SELECT VAR ( field ) AS [ expression ]
FROM table
[ WHERE criteria ]
[ GROUP BY grouping_expression ]
[ HAVING criteria ] - field
- The name of the column that the sample variance of the values is to be taken.
- expression
- The name to be displayed for the resulting variance.
- table
- The name of the table the information is being retrieved from.
- criteria
- The condition(s) that dictate which rows are to be calculated.
- grouping_expression
- An optional parameter that specifies a set of columns on which to group matching data.
The VAR function finds the variance by using a portion, called a sample, of the total number of values in a field.
This is a time saver when dealing with extremely large tables and can be shown to be statistically valid. In comparison, the VARP function uses all of the values to calculate the variance. There must be at least two values in the field or the variance will not be calculated and a NULL is returned.
Examples
Code:
SELECT VAR(Age) AS [VarAge]
FROM MediCarePatients
Output:
VarAge 384.1061
(1 row(s) affected)
Explanation:
This code finds the variance of the age of the MediCare patients in a hospital (by using a sample) and stores that information in 'VarAge'.
Language(s): MS SQL Server
See Also:
