Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

Aggregate function on a column supplied by a variable

Posted on 2011-03-01
3
210 Views
Last Modified: 2012-05-11
Here is the dilemma.  I have a stored procedure where I need to grab the AVG of a column containing chemistry data.   There is a separate column for all chemistries we track, roughly 26 of them.  C, ZR, Pb, etc. etc.   This stored procedure needs to just do the avg on the chemistry that the user selects.

Is there a way to do this dynamically by passing the column name as a variable?

Below is a version that I attempted, but I get the error:

The name 'SELECT TOP 1 Avg[C] FROM XXXX GROUP BY Type' is not a valid identifier.
DECLARE @SQL2 varchar(1000)

BEGIN

DECLARE @in nvarchar(5)
SET @in = 'C'

SET @SQL2 = 'SELECT TOP 1 Avg['+@in+'] FROM XXXX GROUP BY Type'
EXEC @SQL2
END

Open in new window

0
Comment
Question by:hscast
  • 2
3 Comments
 
LVL 8

Accepted Solution

by:
Forefront_Data_Solutions earned 500 total points
ID: 35007461
Use parentheses instead:  

SET @SQL2 = 'SELECT Avg('+@in+') FROM XXXX GROUP BY Type'

I also don't think you need "Top 1"
0
 

Author Comment

by:hscast
ID: 35007493
Nevermind.  Added ( after Avg and ) after the end bracket and it worked.
0
 

Author Comment

by:hscast
ID: 35007496
Whoops.  Quick answer Forefront!  I'll give you the points still.
0

Featured Post

Ransomware: The New Cyber Threat & How to Stop It

This infographic explains ransomware, type of malware that blocks access to your files or your systems and holds them hostage until a ransom is paid. It also examines the different types of ransomware and explains what you can do to thwart this sinister online threat.  

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Why is this different from all of the other step by step guides?  Because I make a living as a DBA and not as a writer and I lived through this experience. Defining the name: When I talk to people they say different names on this subject stuff l…
Slowly Changing Dimension Transformation component in data task flow is very useful for us to manage and control how data changes in SSIS.
Via a live example combined with referencing Books Online, show some of the information that can be extracted from the Catalog Views in SQL Server.
Viewers will learn how to use the SELECT statement in SQL and will be exposed to the many uses the SELECT statement has.

856 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question