[Okta Webinar] Learn how to a build a cloud-first strategyRegister Now

x
?
Solved

Easy load a two dimensional array from a SqlDataReader

Posted on 2010-09-15
8
Medium Priority
?
556 Views
Last Modified: 2012-06-22
I want to read two columns from a SqlDataReader into a dynamic two-dimensional string array - or some way to easily persist the data so I can iterate through it. What is the best way to do this?

example:

var someCollection = new someCollection();
while (reader.Read()
{
   someCollection.Add(reader["col1"].ToString(),reader["col2"].toString());
}
0
Comment
Question by:purplesoup
  • 3
  • 2
  • 2
  • +1
8 Comments
 
LVL 7

Expert Comment

by:klakkas
ID: 33682103
Why not put it in a Datatable and use this to iterate through your data?

0
 
LVL 20

Expert Comment

by:Daniel Van Der Werken
ID: 33682109
There are bunches of ways to do this.  If you want a Key/Value pairing, you can use a HashTable.  Myself, I might create a struct with the values like:

public struct MyStruct
{
    string ColumnOneValue;
    string ColumnTwoValue;
}

List<MyStruct> myStructList = new List<MyStruct>();

Then, in the loop:

MyStruct ms = new MyStruct();
ms.ColumnOneValue = reader["col1"].ToString();
ms.ColumnTwoValue = reader["col2"].ToString();

and

if ( !myStructList.Contains( ms ) )
{
   myStructList.Add( ms ) );
}

or you could use a HashSet instead of a List.
0
 
LVL 8

Accepted Solution

by:
Gururaj Badam earned 1000 total points
ID: 33682268
I'm proposing to use Anonymous Types if you don't to bother for the Type of each item. And also notice I'm not using .ToString() as it may throw exception if the value is null.
IList list = new List();
            while (reader.Read())
                list.Add(new { ColumnOne = (string)reader["col1"], ColumnTwo = (string) reader["col2"] });

Open in new window

0
Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

 

Author Comment

by:purplesoup
ID: 33682576
klakkas - yes a DataTable is an option, I'd like to understand what the other options are first before using it.

Dan7el - I don't want key/value pairing so no hashtable, I'd also rather not create a separate structure just to hold the values.

Novice_Novice - I was wondering about anonymous types, this might be the way to go, I'd like to use strong typing though with strings.

I'll keep this open a little longer and see if anything else comes up..
0
 
LVL 8

Expert Comment

by:Gururaj Badam
ID: 33682886
It will be good to know your intent to help us understand better and suggest the best.
0
 

Author Comment

by:purplesoup
ID: 33689564
I'm iterating through a master/detail table relationship.
0
 
LVL 8

Expert Comment

by:Gururaj Badam
ID: 33689581
No, actually I meant what you will do with this list?
0
 
LVL 7

Assisted Solution

by:klakkas
klakkas earned 1000 total points
ID: 33689612
I will stick with the suggestion of the datatable for your problem purplesoup, for the following reasons:

1. It is easy to load the data to the datatable from the DataReader.
2. It is very easy to iterate through the data
3. You do not worry about datatypes, DataRowItem can contain anything.
4. Important: You can use the Datatable.Select method to either select some data off your datatable or even sort it automatically.
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

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

Exception Handling is in the core of any application that is able to dignify its name. In this article, I'll guide you through the process of writing a DRY (Don't Repeat Yourself) Exception Handling mechanism, using Aspect Oriented Programming.
It was really hard time for me to get the understanding of Delegates in C#. I went through many websites and articles but I found them very clumsy. After going through those sites, I noted down the points in a easy way so here I am sharing that unde…
this video summaries big data hadoop online training demo (http://onlineitguru.com/big-data-hadoop-online-training-placement.html) , and covers basics in big data hadoop .
Are you ready to place your question in front of subject-matter experts for more timely responses? With the release of Priority Question, Premium Members, Team Accounts and Qualified Experts can now identify the emergent level of their issue, signal…
Suggested Courses
Course of the Month19 days, 8 hours left to enroll

873 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