title: Error CS0234 The type or namespace name 'Reporting' does not exist in the namespace 'Microsoft' (Are you missing an assembly reference?)
body: <p>I downloaded this project and database but when I run it I get this error, Can you please help me to fix this? I really appreciate your help.</p>
  <p>I have attached the source code and database, please take a look.
  <a href="https://gofile.io/d/9TZvQV" rel="nofollow noreferrer">https://gofile.io/d/9TZvQV</a>
  Thank you!</p>
  <p><a href="https://i.stack.imgur.com/tzzdl.jpg" rel="nofollow noreferrer">enter image description here</a></p>
  <pre><code>using System;
  using System.Collections.Generic;
  using System.ComponentModel;
  using System.Data;
  using System.Drawing;
  using System.Linq;
  using System.Text;
  using System.Threading.Tasks;
  using System.Windows.Forms;
  using System.Configuration;
  using System.Data;
  using System.Data.SqlClient;
  using Microsoft.Reporting.WinForms;
  
  namespace DBApplication
  {
      public partial class frmBilling : Form
      {
          SqlConnection con;
          SqlDataAdapter da;
          SqlCommand com;
          SqlDataReader dreader;
          DataSet ds;
          DataTable dt;
          DataRow dr;
          string sql;
          int quantity;
          ReportDataSource rds;
          ReportParameterCollection repParams;
          public frmBilling()
          {
              InitializeComponent();
              string constr = ConfigurationManager.ConnectionStrings[&quot;constr&quot;].ToString();
              con = new SqlConnection(constr);
              loadCategory();
          }
  
          private void loadCategory()
          {
              sql = &quot;SELECT CategoryID,CategoryName FROM Categories&quot;;
              da = new SqlDataAdapter(sql, con);
              ds = new DataSet();
              da.Fill(ds, &quot;Categories&quot;);
              dt = ds.Tables[&quot;Categories&quot;];
              dr = dt.NewRow();
              dr[0] = &quot;-1&quot;;
              dr[1] = &quot;--Select Category--&quot;;
              dt.Rows.InsertAt(dr, 0);
              cmbCategory.DisplayMember = &quot;CategoryName&quot;;
              cmbCategory.ValueMember = &quot;CategoryID&quot;;
              cmbCategory.DataSource = dt;
          }
  </code></pre>