Solved

Passing fieldnames as parameter in stored procedure

Posted on 2016-10-04
4
48 Views
Last Modified: 2016-10-04
Hi,

I have a sp like this
 
ALTER PROCEDURE [dbo].[st_test] @SelectString as varchar(8000)

as
select
@SelectString

from t1
ORDER BY userid

Open in new window


When I exec this sp
exec [st_test] "some string"

It does not return the value I need, instead, it returns number of rows in the table with "some string" as values.  Any ideas?  thanks
0
Comment
Question by:mcrmg
4 Comments
 
LVL 33

Assisted Solution

by:Norie
Norie earned 100 total points
ID: 41828608
Try something like this.


SET @sql = 'SELECT ' + @SelectString + ' FROM t1 ORDER BY userid'

sp_executesql @sql
0
 
LVL 69

Accepted Solution

by:
Éric Moreau earned 250 total points
ID: 41828612
you need to use dynamic SQL to be able to do that. have a look at http://www.codeproject.com/Articles/20815/Building-Dynamic-SQL-In-a-Stored-Procedure
0
 
LVL 33

Assisted Solution

by:ste5an
ste5an earned 150 total points
ID: 41828613
First of all: Such a generic procedure is not useful under most circumstances..

The only way to do it, is by using dynamic SQL, which has it's problems (scope, permissions, execution plans):

ALTER PROCEDURE [dbo].[st_test]
    @Columns AS NVARCHAR(MAX)
AS
    DECLARE @SQL NVARCHAR(MAX) = N'
        SELECT @SelectString
        FROM t1;'
    SET @SQL = REPLACE(@SQL, '@Columns', @Columns)
    EXECUTE (@SQL);

Open in new window


Read also Erland's excellent article: The Curse and Blessings of Dynamic SQL
0
 

Author Closing Comment

by:mcrmg
ID: 41828621
thank you
0

Featured Post

VMware Disaster Recovery and Data Protection

In this expert guide, you’ll learn about the components of a Modern Data Center. You will use cases for the value-added capabilities of Veeam®, including combining backup and replication for VMware disaster recovery and using replication for data center migration.

Question has a verified solution.

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

JSON is being used more and more, besides XML, and you surely wanted to parse the data out into SQL instead of doing it in some Javascript. The below function in SQL Server can do the job for you, returning a quick table with the parsed data.
For both online and offline retail, the cross-channel business is the most recent pattern in the B2C trade space.
Via a live example, show how to set up a backup for SQL Server using a Maintenance Plan and how to schedule the job into SQL Server Agent.
Viewers will learn how to use the SELECT statement in SQL and will be exposed to the many uses the SELECT statement has.

914 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

Need Help in Real-Time?

Connect with top rated Experts

20 Experts available now in Live!

Get 1:1 Help Now