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 option   In the past  I ve used the following two methods to accomplish this   Method 1  int numberOfRecords   0  DataRow   rows   rows   dtFoo Select  IsActive    Y     numberOfRecords   rows Length   Console WriteLine  Count      numberOfRecords ToString       Method 2  int numberOfRecords   0   foreach  DataRow row in dtFoo Rows        if  row  IsActive   ToString       Y                 numberOfRecords             Console WriteLine  Count      numberOfRecords ToString       My shop is trying to standardize on a few things and this is one issue that has come up   I m wondering which of these methods is best in terms of performance  and why    as well as which is most commonly used   Also  are there better ways to achieve the desired results

User · Answer

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.

User · Answer

int row count   dt Rows Count

User · Answer

int numberOfRecords   0   numberOfRecords   dtFoo Select   Length   MessageBox Show numberOfRecords ToString

User · Answer

Not sure if this is faster  but at least it s shorter     int rows   new DataView dtFoo   IsActive    Y     IsActive       DataViewRowState CurrentRows  Table Rows Count

User · Answer

int numberOfRecords   DTb Rows Count  int numberOfColumns   DTb Columns Count

User · Answer

Try this  int numberOfRecords   dtFoo Select  IsActive    Y    Count lt DataRow gt         Console WriteLine  Count      numberOfRecords ToString

User · Answer

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   gt  x  IsActive   ToString       Y   ToList   Count    Note this requires including System Linq

User · Answer

object count  dtFoo Compute  count IsActive     IsActive  Y

[c#] Getting a count of rows in a datatable that meet certain criteria

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