title: mysql parameters passing not implementing asp.net
body: <p>I have 3 tables 1>disease_table [columns=] (disease_id,disease_name)2>symptom_table [columns=] (symptom_id,symptom_name)3>disease_symptom [columns=] (disease_id,symptom_id)
  there is a checkboxlist on my web page which has symptoms where text=fever, value='fever'..and so on but the problem is that I get no output when I pass parameter to the sql stmt., it doesn't give any output.Also if I pass static parameter (if I choose to pass all the available symptoms) it gives me repeated disease names.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>protected void Button1_Click(object sender, EventArgs e)
  {
      MySqlConnection connection = new MySqlConnection(ConfigurationManager.ConnectionStrings["myconstring"].ConnectionString);
      connection.Open();
      symptons = String.Join(", ", CheckBoxList1.Items.Cast&lt;ListItem&gt;().Where(i =&gt; i.Selected).Select(i =&gt; i.Value).ToArray());
      Label3.Text = symptoms;
      MySqlCommand cmd = new MySqlCommand("select d.dname from disease d inner join diseasesymptom ds on ds.did = d.did inner join symptom s on s.sid = ds.sid where s.sname in (@pSymptoms)", connection);
       cmd.Parameters.AddWithValue("@pSymptoms", symptoms);
      using (MySqlDataAdapter sda = new MySqlDataAdapter())
      {
          cmd.Connection = connection;
          sda.SelectCommand = cmd;
          using (DataTable dt = new DataTable())
          {
              sda.Fill(dt);
              GridView1.DataSource = dt;
              GridView1.DataBind();
          }
      }
  }
  </code></pre>
  
  <p>sql stmt :</p>
  
  <pre><code>selectd.name, d.disease_id 
  from Disease d
  inner join DiseaseSymptom ds on ds.disease_id = d.disease_id
  inner join Symptom s on s.symptom_id = ds.symptom_id
  where s.name in ('Fever');
  </code></pre>
  
  <p>output: if I pass all the parameters(static) then I get all available diseases multiple times (e.g :if disease 'd1' has 2 symptoms and I choose 2 of those symptoms that disease 'd1' is displayed twice)</p>