Question

I have the following:

    SqlConnection con = new SqlConnection(strConn);
    DataSet ds = new DataSet();
    SqlDataAdapter myda = new SqlDataAdapter("SELECT [Key], [Value] FROM [data_LookupValues] where Category = 'CanadaProvinces' ", con);
    myda.Fill(ds);
    ddlState.DataSource = ds;
    ddlState.DataTextField = "Value";
    ddlState.DataValueField = "Key";
    ddlState.DataBind(); 

I am stuck as I need to put a string value of CanadaProvinces within the SqlDataAdapter.

Is there a easy way of doing this? I get an error when I do it the way I have it.

Answer 1

The proper way would be to do a number of things:

1. wrap your disposable objects into using blocks
2. use a separate SqlCommand object and use a parametrized query (instead of concatenating together your SQL)
3. since you’re only returning a single set of data – use a DataTable instead of the much “heavier” DataSet
4. separate the fetching of the data into its own method – and just call the from your web page – makes it universally useable, too! (will work for other things – not just CanadaProvinces)

So your code should be something like this:

private DataTable FetchData(string categoryValue)
{
   string query = "SELECT [Key], [Value] FROM [data_LookupValues] where Category = @Category";

   using (SqlConnection con = new SqlConnection(strConn))
   using (SqlCommand cmd = new SqlCommand(query, con))
   {
       cmd.Parameters.Add("@Category", SqlDbType.VarChar, 50).Value = categoryValue;

       SqlDataAdapter myda = new SqlDataAdapter(cmd);
       DataTable result = new DataTable();

       myda.Fill(result);
       return result;
    }
}

and then in your ASPX web’s code-behind, use something like this:

DataTable tblCanadaProvinces = FetchData('CanadaProvinces');  

ddlState.DataSource = tblCanadaProvinces;
ddlState.DataTextField = "Value";
ddlState.DataValueField = "Key";
ddlState.DataBind(); 

and be done with it. Now you can call your FetchData method to retrieve any possible category in your lookup table!