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

Question

count item(exp: number of laptoppc) 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 P · 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 :)