Is it possible to select all the data in a datatable and store it in an array?

Question

0.00/5 (No votes)

See more:

Generally speaking I created a code that accesses multiple servers and reads the data from those servers.
Currently I have extracted all the data as a string from the DataTables and display it using ListView, however I was wondering if there was a way to store the data in a array so that I can do basic math operations later.

What I have tried:

for (int i = 0; i < DataTable1.Rows.Count; i++)
{
    var resultTest = DataTable1.AsEnumerable().Select(r => r.Field<string>("Name")).ToArray();
    listView1.Items.Add(resultTest[i].ToString());
}

Posted 15-Oct-18 23:23pm

Graeme Cooper

Updated 15-Oct-18 23:50pm

Add a Solution

Comments

Graeme Cooper 16-Oct-18 5:25am

Just so you know I'm aware that the code above displays a single column instead of the entire dataset. I'm just having trouble thinking of a possible solution.

Graeme Cooper 16-Oct-18 5:44am

I'm sorry My follow codeproject user, I'm a very impatient person these days. I have solved my own problem 5mins after posting this question.

3 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Accepted Answer · 2018-10-15T23:45:00

Um.
resultTest is an array: you will get exactly the same results if you do this:

string[] resultTest = DataTable1.AsEnumerable().Select(r => r.Field<string>("Name")).ToArray();

So why is this giving you a problem?

But please, start by looking at your code: why are you looping through all rows and converting the whole DataTable each time you go round the loop, only to use a single row, and throw away the rest?
You could just say this:

for (int i = 0; i < DataTable1.Rows.Count; i++)
{
    listView1.Items.Add(DataTable1.Rows[i]["Name"].ToString());
}

and get the same results.

If you want an array of numeric values, then you can just discard the loop, modify the single line of Linq you have and TryParse or Parse the column to a number - but columns called "Name" do not generally contain numeric data!

#realJSOP · Accepted Answer · 2018-10-15T23:50:00

Instead of messing around with trying to shortcut it, move the data into a List of objects. At that point, it will be easier to manipulate. You're spending so much time trying to use the data directly from a DataTable that you're loosing your way.

C#

public class ItemList : List<MyItem>
{
    public ItemList(DataTable dt)
    {
        foreach(DataRow row in dt.Rows)
        {
            this.Add(new MyItem(row));
        }
    }
}

public class MyItem
{
    // properties for each row column go here

    public MyItem(DataRow row)
    {
        // populate the properties from the row
    }
}

// usage

ItemList myItems = new ItemList(DataTable1);

If you want to get a little fancier, you could retrieve the data (from a database, I'm assuming) in the List constructor, which would simplify the outward facing code even more.

Graeme Cooper · Accepted Answer · 2018-10-15T23:49:00

for (int i = 0; i < DataTable1.Rows.Count; i++)
{
    var resultTest1 = DataTable1.AsEnumerable().Select(r => r.Field<string>("column Name")).ToArray();
    var resultTest2 = DataTable1.AsEnumerable().Select(r => r.Field<string>("Column Name")).ToArray();
    var resultTest3 = DataTable1.AsEnumerable().Select(r => r.Field<string>("Column Name")).ToArray();
    var resultTest4 = DataTable1.AsEnumerable().Select(r => r.Field<string>("Column Name")).ToArray();
    listView1.Items.Add(resultTest1[i].ToString() + " " + resultTest2[i].ToString() + " " + resultTest3[i].ToString() + " " + resultTest4[i].ToString());
}

Note:

var resultTest2 = DataTable1.AsEnumerable().Select(r => r.Field<int?>("Column Name")).ToArray();

read column integer values

Is it possible to select all the data in a datatable and store it in an array?

3 solutions

Solution 1

Solution 3

Solution 2

Add your solution here

Preview 0