SQL Server/T-SQL Tutorial/Analytical Functions/VAR
The VAR() return the measure of how far the extreme low range or high range value is from the middle
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or mean value of the range, weighted by the greatest concentration of similar values. 11> 12> Create Table MyValues (MyValue Float) 13> GO 1> 2> Insert Into MyValues (MyValue) SELECT 2 3> Insert Into MyValues (MyValue) SELECT 3 4> Insert Into MyValues (MyValue) SELECT 4 5> Insert Into MyValues (MyValue) SELECT 5 6> Insert Into MyValues (MyValue) SELECT 6 7> GO (1 rows affected) (1 rows affected) (1 rows affected) (1 rows affected) (1 rows affected) 1> 2> SELECT VAR(MyValue) FROM MyValues 3> GO
2.5
(1 rows affected) 1> 2> INSERT INTO MyValues (MyValue) SELECT 3 3> INSERT INTO MyValues (MyValue) SELECT 4 4> INSERT INTO MyValues (MyValue) SELECT 4 5> INSERT INTO MyValues (MyValue) SELECT 4 6> INSERT INTO MyValues (MyValue) SELECT 5 7> GO (1 rows affected) (1 rows affected) (1 rows affected) (1 rows affected) (1 rows affected) 1> 2> SELECT VAR(MyValue) FROM MyValues 3> GO
1.3333333333333333
(1 rows affected) 1> 2> 3> drop table MyValues; 4> GO</source>
VAR computes the variance of all the values listed in a column or expression.
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The aggregate function VARP computes the variance for the population of all the values listed in a column or expression. 11> 12> CREATE TABLE employee( 13> id INTEGER NOT NULL PRIMARY KEY, 14> first_name VARCHAR(10), 15> last_name VARCHAR(10), 16> salary DECIMAL(10,2), 17> start_Date DATETIME, 18> region VARCHAR(10), 19> city VARCHAR(20), 20> managerid INTEGER 21> ); 22> GO 1> INSERT INTO employee VALUES (1, "Jason" , "Martin", 5890,"2005-03-22","North","Vancouver",3); 2> GO (1 rows affected) 1> INSERT INTO employee VALUES (2, "Alison", "Mathews",4789,"2003-07-21","South","Utown",4); 2> GO (1 rows affected) 1> INSERT INTO employee VALUES (3, "James" , "Smith", 6678,"2001-12-01","North","Paris",5); 2> GO (1 rows affected) 1> INSERT INTO employee VALUES (4, "Celia" , "Rice", 5567,"2006-03-03","South","London",6); 2> GO (1 rows affected) 1> INSERT INTO employee VALUES (5, "Robert", "Black", 4467,"2004-07-02","East","Newton",7); 2> GO (1 rows affected) 1> INSERT INTO employee VALUES (6, "Linda" , "Green" , 6456,"2002-05-19","East","Calgary",8); 2> GO (1 rows affected) 1> INSERT INTO employee VALUES (7, "David" , "Larry", 5345,"2008-03-18","West","New York",9); 2> GO (1 rows affected) 1> INSERT INTO employee VALUES (8, "James" , "Cat", 4234,"2007-07-17","West","Regina",9); 2> GO (1 rows affected) 1> INSERT INTO employee VALUES (9, "Joan" , "Act", 6123,"2001-04-16","North","Toronto",10); 2> GO (1 rows affected) 1> 2> select * from employee; 3> GO id first_name last_name salary start_Date region city managerid
---------- ---------- ------------ ----------------------- ---------- -------------------- -----------
1 Jason Martin 5890.00 2005-03-22 00:00:00.000 North Vancouver 3
2 Alison Mathews 4789.00 2003-07-21 00:00:00.000 South Utown 4
3 James Smith 6678.00 2001-12-01 00:00:00.000 North Paris 5
4 Celia Rice 5567.00 2006-03-03 00:00:00.000 South London 6
5 Robert Black 4467.00 2004-07-02 00:00:00.000 East Newton 7
6 Linda Green 6456.00 2002-05-19 00:00:00.000 East Calgary 8
7 David Larry 5345.00 2008-03-18 00:00:00.000 West New York 9
8 James Cat 4234.00 2007-07-17 00:00:00.000 West Regina 9
9 Joan Act 6123.00 2001-04-16 00:00:00.000 North Toronto 10
(9 rows affected) 1> 2> SELECT VAR(salary) variance_of_budgets 3> FROM employee 4> 5> 6> 7> drop table employee; 8> GO variance_of_budgets
755682.77777777612
(1 rows affected) 1></source>
