title: The conversion of the varchar value '5566778891' overflowed an int column
body: <p>I am using SQL Server database and there's a column named Cell(VARCHAR) data type. While reading using <code>reader.Read()</code> I get the Conversion error. Can anyone kindly explain the reason for the error?</p>
  
  <p>This is my code:</p>
  
  <pre><code>string myConnection = dbController.connectionString;
          string query1 = "SELECT ID, Name from Manager Where Cell = " + managerNo.Text;
          using (var conn = new SqlConnection(myConnection))
          using (var cmd = new SqlCommand(query1, conn))
          {
              conn.Open();
              SqlDataReader reader = cmd.ExecuteReader();
  
              while (reader.Read())
              {
                  managerID = reader.GetString(0);
                  mgrID.Text = managerID;
                  managerNames.Text = reader.GetString(1);
              }
              conn.Close();
          }
  </code></pre>
  
  <p>I am reading the value from a textbox (managerNo). I have tested the query on SQL Server Management Studio as well:</p>
  
  <pre><code>select Name, DOB
  from Contact
  where Cell = 1233453411
  </code></pre>
  
  <p>When I use <code>Cell = 1233453411</code> without the value as string I get the conversion error, however using <code>Cell = '1233453411'</code> as a string the result is fetched.</p>
  
  <p>Whats the reason for this and how to solve this issue.</p>
  
  <p>Thanks.</p>