how to count a distinct of item from a database table?

Question

count item(exp: number of laptop,pc) from a database (microsoft sql server 2012) and display it in a textbox or richtextbox in a form in(visual studio 2013) vb.net . thank youuuu friendss...

Jaipal Reddy · Answer

The following query returns aDistinct count of laptops. SELECT COUNT(DISTINCT LapTop) AS Count, FROM tbl_Laptop oputput like : 10 To display it in TextBox SqlCommand cmd = new SqlCommand(" SELECT COUNT(DISTINCT LapTop) AS Count, FROM tbl_Laptop ", con); SqlDataAdapter adp = new SqlDataAdapter(cmd); DataSet ds = new DataSet(); adp.Fill(ds); txtBox.text = ds. .Tables[0].Rows[1]["columnName"].ToString();

Upendra Pratap Shahi · Answer

SqlCommand cmd = new SqlCommand ( "SELECT COUNT(DISTINCT LapTop) AS LaptopCount FROM tbl_Laptop" , "your connection varriable" ); SqlDataAdapter da= new SqlDataAdapter (cmd); DataSet ds = new DataSet (); da.Fill(ds); txtCount.Text = ds.Tables[0].Rows[1][ "LaptopCount" ]. ToString ();

King Umar · Answer

thank you Mr Thava :) I appreciate it a lot

Thavaselvan Palanivel · Answer

use linq, var dt1 = _datatable.AsEnumerable().Select(p => new { _ID = p.Field string >( "ID" ), _Name = p.Field string >( "Name" ), _Paid = p.Field string >( "Paid" ), _Employed = p.Field string >( "Employed" ) ----- ------ }); var idr2 = (from xx in dt1 where xx._Employed == "Y" orderby xx._Name select xx._Name).Distinct();

King Umar · Answer

thanks jaipal , it help me a lott :)