Getting a count of rows in a datatable that meet certain criteria

Question

I have a datatable, dtFoo, and would like to get a count of the rows that meet a certain criteria.

EDIT: This data is not stored in a database, so using SQL is not an op

Answer 1

int numberOfRecords = 0;

numberOfRecords = dtFoo.Select().Length;

MessageBox.Show(numberOfRecords.ToString());

Answer 2

int numberOfRecords = DTb.Rows.Count;
int numberOfColumns = DTb.Columns.Count;

Answer 3

int row_count = dt.Rows.Count;

Answer 4

If the data is stored in a database it will be faster to send the query to the database instead of getting all data and query it in memory.

A third way to do it will be linq to datasets, but i doubt any of these 3 methods differ much in performance.

Answer 5

Try this

int numberOfRecords = dtFoo.Select("IsActive = 'Y'").Count<DataRow>();    
Console.WriteLine("Count: " + numberOfRecords.ToString());

Answer 6

One easy way to accomplish this is combining what was posted in the original post into a single statement:

int numberOfRecords = dtFoo.Select("IsActive = 'Y'").Length;

Another way to accomplish this is using Linq methods:

int numberOfRecords = dtFoo.AsEnumerable().Where(x => x["IsActive"].ToString() == "Y").ToList().Count;

Note this requires including System.Linq.