Question

Basically, the idea is to match data from one DataTable with another.
In the first DT, there are 20 different columns in one row that I create an array from, and there is another DT with thousands of rows, two columns each. I need to select all of those rows in the second DT that are found among all of the 20 different variables in the array (so, I go row by row in the first table).

Can I do this in one query?

for (int x = 0; x < 20; x++) //this fills up the array from the 20 columns of dt1
{
   numbers[x] = Convert.ToInt16(dt1.Rows[i]["n" + (x+1)]);
}
var filtered = dt2.Select("Col1 = " + (any of the numbers[]) + " AND Col2 = " + (any of the numbers[]));

So clearly the line in question is the last one. I’m not sure if it’s possible to do so.

I’m new here and I’m new to C# as well.
Thank you for your help.

Answer 1

You could use this SQL on DataTable:

var numbersAsString = numbers.Select(x => x.ToString()).Aggregate((x,y) => x + "," + y);
var filtered = dt2.Select("Col1 in (" + numbersAsString  + ") AND Col2 in (" + numbersAsString  + ")");

First you create string from your Array that looks like this: ‘1,3,4,5’ and then checks in SQL if Col1 or Col2 value is in the array.