Solved

Stored Procedure updating columns Dynamically

Posted on 2012-04-02
2
284 Views
Last Modified: 2012-08-14
I have a stored procedure that I want to have save a value to a column based on the input I throw at it. I'm checking for existing column and datatype.

@Registration_ID NUMERIC
,@ColumnName VARCHAR(255)
,@ColumnValue VARCHAR(255)
,@ColumnDataType VARCHAR(255) OUTPUT
      

      SELECT @ColumnDataType = [Data_Type]
      FROM INFORMATION_SCHEMA.COLUMNS
      WHERE TABLE_NAME='Checklist'
      AND COLUMN_NAME=@ColumnName
      IF @ColumnDataType <> ''

----- @ColumnDataType here is set to a value of 'bit'

                        UPDATE [dbo].[Checklist]
                        SET @ColumnName =@ColumnValue
                              ,[Modified_Timestamp] = CURRENT_TIMESTAMP
                              ,[Modified_Action] = 'Update'
                        WHERE [Registration_ID] = @Registration_ID

       END


However when I run the SP, it does not update the column to the value I supply.

I tried using CAST with a dynamic SQL but it ended up in misery, so I'm avoiding that route unless I have to.
The SQL I used was:

SET @ColumnName = CAST(@ColumnValue AS @ColumnDataType)

Any suggestions as to what I'm doing wrong?
0
Comment
Question by:Rodrigo Munera
2 Comments
 
LVL 7

Accepted Solution

by:
micropc1 earned 500 total points
ID: 37799136
Since @ColumnName is not a field name you need to execute the dynamic update statement in either the EXEC command or the sp_executesql stored procedure.

Like...

EXEC('UPDATE [dbo].[Checklist] SET ' + @ColumnName + '=' + @ColumnValue + '
	,[Modified_Timestamp] = CURRENT_TIMESTAMP
	,[Modified_Action] = ''Update'' 
	WHERE [Registration_ID] = ' + @Registration_ID)

Open in new window


http://www.mssqltips.com/sqlservertip/1160/execute-dynamic-sql-commands-in-sql-server/
0
 
LVL 4

Author Closing Comment

by:Rodrigo Munera
ID: 37800834
Thank YOU!
I had started going in this direction but was thinking about the string wrong.
Your example cleared up for me a lot and helped me get to a working solution!

Ended up using SP_EXECUTESQL, that way I could declare the variables I was passing and was able to type them correctly :) thankyouthankyouthankyou!!!

This is what the final code ended up looking like:


SET @SQLString=N'UPDATE [dbo].[Checklist]
                              SET '+@ColumnName+' = @ColValue
                                    ,[Modified_Operator] = @Oper
                                    ,[Modified_Timestamp] = CURRENT_TIMESTAMP
                                    ,[Modified_Action] = ''Update''
                              WHERE [Registration_ID] = @Reg_ID';
SET @Params=N'@ColValue '+@ColumnDataType+'
                         ,@Oper VARCHAR(10)
                         ,@Reg_ID NUMERIC';

EXECUTE SP_EXECUTESQL      @SQLString
                                       ,@Params
                                       ,@ColValue=@ColumnValue
                                       ,@Oper=@Operator
                                       ,@Reg_ID=@Registration_ID;
0

Featured Post

Best Practices: Disaster Recovery Testing

Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.

Question has a verified solution.

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

Everyone has problem when going to load data into Data warehouse (EDW). They all need to confirm that data quality is good but they don't no how to proceed. Microsoft has provided new task within SSIS 2008 called "Data Profiler Task". It solve th…
This article shows gives you an overview on SQL Server 2016 row level security. You will also get to know the usages of row-level-security and how it works
Via a live example, show how to extract insert data into a SQL Server database table using the Import/Export option and Bulk Insert.
Viewers will learn how to use the SELECT statement in SQL and will be exposed to the many uses the SELECT statement has.

773 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