SQL server Count Aggregate

Count Aggregate:

Just declare a table, say

DECLARE @t table

(

id int identity(1,1),

value varchar(50)

)

Insert some values,

INSERT INTO @t values(NULL)

INSERT INTO @t values(NULL)

INSERT INTO @t values(NULL)

INSERT INTO @t values('1')

INSERT INTO @t values('2')

INSERT INTO @t values('3')

What is the output?

SELECT count(id), count(value) FROM @t

It's 6,3 actually because, The Count aggregate does not include NULL values, so the count will be 3 rows for the 2nd column