[2 days left] What’s wrong with your cloud strategy? Learn why multicloud solutions matter with Nimble Storage.Register Now

x
?
Solved

Multiple parameters in a Select statement at run time

Posted on 2006-07-13
4
Medium Priority
?
262 Views
Last Modified: 2010-04-16
What is the best way to format a Select statement when the amount of parameter variables are not known until run time?
0
Comment
Question by:fly412s
[X]
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
  • 2
4 Comments
 
LVL 4

Expert Comment

by:DarkXiphoid
ID: 17103039
Make an arraylist with parameters. Like this string[] paramList = new string[]

That way you can add any number of parameters during runtime.

Hope this helps you in the right direction.

Regards,

Robert
0
 
LVL 25

Expert Comment

by:dstanley9
ID: 17103641
Are you talking about a SQL SELECT statement?  AFAIK it's not possible.  The best way I've seen is to use a finite set of VARCHAR parameters:

CREATE PROCEDURE MyParameterHack
@param1 VARCHAR(500) = null,
@param2 VARCHAR(500) = null,
@param3 VARCHAR(500) = null,
@param4 VARCHAR(500) = null,
@param5 VARCHAR(500) = null,
@param6 VARCHAR(500) = null
AS
...

However, SQL does support "optional" parameters, which may be a better option.

What is the procedure going to do?  Maybe there's an alternate method than variable parameters



0
 

Author Comment

by:fly412s
ID: 17103700
I'm using ADO.net.  I'm using the System.Data.OleDb namespace.  I'm connecting to a flat database file (.csv).  
0
 
LVL 25

Accepted Solution

by:
dstanley9 earned 2000 total points
ID: 17103811
Then you can build it using string concatenation.

For example, to use a dynamic WHERE clause, use arrays for field names and values:

string[] fields;
string [] values;

// build arrays of fields and values

string sql = "SELECT * FROM flatfile WHERE " 
for(int i=0; i<numParams; i++)
{
  sql += "[" + fields[i] + "] = @Param" + i.ToString() ;
  if (i<numparams-1)
    sql += " AND ";
}
OleDbCommand command = new OleDbCommand(sql);

for(int i=0; i<numParams; i++)
{
  command.Parameters.Add("@Param" + i.ToString(),values[i]);
}



0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

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

Extention Methods in C# 3.0 by Ivo Stoykov C# 3.0 offers extension methods. They allow extending existing classes without changing the class's source code or relying on inheritance. These are static methods invoked as instance method. This…
In order to hide the "ugly" records selectors (triangles) in the rowheaders, here are some suggestions. Microsoft doesn't have a direct method/property to do it. You can only hide the rowheader column. First solution, the easy way The first sol…
In this video, Percona Solution Engineer Dimitri Vanoverbeke discusses why you want to use at least three nodes in a database cluster. To discuss how Percona Consulting can help with your design and architecture needs for your database and infras…
We’ve all felt that sense of false security before—locking down external access to a database or component and feeling like we’ve done all we need to do to secure company data. But that feeling is fleeting. Attacks these days can happen in many w…
Suggested Courses

649 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