How to get average of 3 consecutive result in crystal report (Date:19-05-2015)

Question

1.00/5 (2 votes)

See more:

ID + Avg    + average 3 consecutive 
A  +  60.0  +    --             +
B  +  62.0  +    --             +
C  +  63.0  +    61.7           + <- Average of (ABC)
D  +  59.0  +    61.3           + <- Average of (BCD)
E  +  58.0  +    60.0           + <- Average of (CDE)
F  +  60.0  +    59.0           + <- Average of (DEF)
G  +  61.0  +    59.7           + <- Average of (EFG)

In my report i am looking for this result (3 rd column)
i have the 1st and 2nd column i cannot make the third column(average 3 consecutive ) in crystal report.

Please help...

Thanks in advance

Posted 18-May-15 20:57pm

Member 11701417

Updated 20-May-15 3:17am

v4

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Kornfeld Eliyahu Peter · Answer 1 · 2015-05-18T22:53:00

SQL

DECLARE @DATA TABLE 
(
    ID NCHAR(1) NOT NULL,
    AVARAGE FLOAT NOT NULL
)

INSERT  @DATA(ID, AVARAGE)
	SELECT  'A', 60.0
	UNION ALL
	SELECT  'B', 62.0
	UNION ALL
	SELECT  'C', 63.0
	UNION ALL
	SELECT  'D', 59.0
	UNION ALL
	SELECT  'E', 58.0
	UNION ALL
	SELECT  'F', 60.0
	UNION ALL
	SELECT  'G', 61.0

;
WITH ORDERED_TABLE AS
(
	SELECT ID, AVARAGE, ROW_NUMBER() OVER (ORDER BY ID) AS ROWNUMBER FROM @DATA
)

SELECT 
	OT_OUT.ID, 
	OT_OUT.AVARAGE,
	CASE WHEN OT_OUT.ROWNUMBER < 3
		THEN NULL
		ELSE
			(
				SELECT AVG(AVARAGE) 
    				FROM ORDERED_TABLE AS OT_IN
    				WHERE OT_IN.ROWNUMBER IN (OT_OUT.ROWNUMBER, OT_OUT.ROWNUMBER - 1, OT_OUT.ROWNUMBER - 2)
			)
	END AS CONSECUTIVE_AVARAGE
FROM ORDERED_TABLE AS OT_OUT

WITH ORDERED_TABLE AS, declares a CTE where you add to every row a row-number so you can say which hare the previous two rows to use with average computation...
The second part is a simple query based on this CTE to do the computation...