Rolling Averages in Sql Server 2008

Question

I dint get the perfect answer last time and i am still working on the exact output that i need.
I have the two integer columns in my table and i have to calculate averages for those two columns.Hence my output should be 
date col1 col2 AVGcol1 AVGcol2
and the average of each row should be avg(value of current date and sum of last five date). In this case i have more than one row for a single date.That also needs to be considered.
Thanks in Advance!!!!!!

Answer 1

Please follow basic Netiquette and post the DDL we need to answer this. Follow industry and ANSI/ISO standards in your data. You should follow ISO-11179 rules for naming data elements. You should follow ISO-8601 rules for displaying temporal data. We need
to know the data types, keys and constraints on the table. Avoid dialect in favor of ANSI/ISO Standard SQL. And you need to read and download the PDF for: 
https://www.simple-talk.com/books/sql-books/119-sql-code-smells/
>> I did not get the perfect answer last time and I am still working on the exact output that I need. <<
Perhaps you might consider posting DDL and giving us sample date, so we can do your job for you?
>> I have the two integer columns in my table and I have to calculate averages for those two columns. Hence my output should be 
something_date, col1, col2, col1_avg, col2_avg
and the average of each row should be avg(value of current date and sum of last five dates). In this case I have more than one row for a single date. That also needs to be considered.<<
I might have guessed that the generic date was the key, but your narrative says this is not so. Too bad we have no idea what the key might be. Too bad we have no idea about NULLs, either! Why did we have to almost torture you to get anything? Just give us DDL
at the start. 
CREATE TABLE Garbage 
(posting_date DATE NOT NULL, 
 col_1 INTEGER NOT NULL, 
 col_2 INTEGER NOT NULL, 
 PRIMARY KEY (???));
INSERT INTO Garbage 
VALUES
('2014-12-10', 250, 200), 
('2014-12-21', 100, 100), 
('2014-12-21', 150, 300), 
('2014-12-21', 100, 100), 
('2014-12-22', 150, 300), 
('2014-12-23', 100, 100), 
('2014-12-23', 150, 300), 
('2014-12-24', 100, 100), 
('2014-12-24', 150, 300), 
('2014-12-25', 200, 450); 
Here is my guess: sum up each day's postings into G2. Now t34eh date could be a key! Then use G2 with a windows clause to get the prior 5 rows. That is not quite the same as the prior five
days, however, if we have gaps. The RANGE option does not work completely in T-SQL, but we could do an outer join to a calendar table and some other tricks.
WITH G2(posting_date, col_1, col_2)
AS
(SELECT posting_date, SUM(col_1), SUM(col_2) 
 FROM Garbage
GROUP BY posting_date)
SELECT posting_date, 
 col_1,
 AVG(col_1 * 1.00)
 OVER (ORDER BY posting_date 
 ROWS BETWEEN 5 PRECEDING AND CURRENT ROW)
 AS col1_avg, 
 col_2,
AVG(col_2 * 1.00)
 OVER (ORDER BY posting_date 
 ROWS BETWEEN 5 PRECEDING AND CURRENT ROW)
 AS col2_avg
 FROM G2; 
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