Try this

Select
Max(bk_cat)
From
tbl_bk
Where
tbl_bk."linking field" = "table in report"."linking field"

Thanks for reply but it only returns 1 row.

this is default.aspx.cs code ... i have to fetch 1 single row from my database from my table...also i have taken drop down list...and when i m selecting any of the number in drop down ...it is displaying the total tabel attributes which i have selected in the code......here is the code...plse give me correct solution asap......

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    

    protected void Button1_Click(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["crmConnectionString"].ConnectionString);
        con.Open();
        string sql1 = "select MP_ID, DOB , Height , Address , Complexion , Gender from Missing_Person where  (MP_ID = 3 AND First_Name='Ravi') ";
        SqlDataAdapter da = new SqlDataAdapter(sql1,con);
        DataSet ds = new DataSet();
        da.Fill(ds);
        ReportDocument rep_doc = new ReportDocument();
        rep_doc.Load(Server.MapPath("~/FirReport.rpt"));
        rep_doc.SetDataSource(ds.Tables[0]);
        CrystalReportViewer1.ReportSource = rep_doc;
        //Following Statements are Optional
        CrystalReportViewer1.DataBind();
        CrystalReportViewer1.RefreshReport();
    }
    protected void TextBox1_TextChanged(object sender, EventArgs e)
    {

    }
   
}


//" i only want one 1 row attributes to b fetch from database and to b displayed'//