can not convert from sqlclient.sqlcommand to string..

Hi,
As I can see in your code snippets everything is fine, except cmd.ExecuteNonQuery. You can use the ExecuteNonQuery to perform catalog operations (for example, querying the structure of a database or creating database objects such as tables), or to change the data in a database without using a DataSet by executing UPDATE, INSERT, or DELETE statements. Although the ExecuteNonQuery returns no rows, any output parameters or return values mapped to parameters are populated with data.. Remove it from your code. It'll work properly. Try this:

SqlConnection con = new SqlConnection(@"Data Source=Desk\SQLEXPRESS;Initial Catalog=Test;Integrated Security=True");
con.Open();
SqlCommand cmd = new SqlCommand("Select * from Customers", con);
//cmd.ExecuteNonQuery();  -- Not required
SqlDataAdapter da = new SqlDataAdapter(cmd, con);
da.Fill(dt);

All the best.
    --Amit

Hi Sandip.
Pleae edit your code line

SqlDataAdapter da = new SqlDataAdapter(cmd, con);  //incorrect

use this

SqlDataAdapter da = new SqlDataAdapter(cmd); //correct

because you have already set SQL Connection to SQLcommand

I think it will help you

Hi,

There is no Constructor for SqlDataAdapter, the takes the cmd and con objects as arguments. The one version we have is, First argument should be the String ( the sql stmt) and the second is the SqlConnection object.

The Other Version of the Constructor I have shown below is , taking only one Parameter , the SqlCommand Object.

The below is the modified code...

try
{
    SqlConnection con = new SqlConnection(@"Data Source=Desk\SQLEXPRESS;Initial Catalog=Test;Integrated Security=True");
    con.Open();
    SqlCommand cmd = new SqlCommand("Select * from Customers", con);
    cmd.ExecuteNonQuery();
    SqlDataAdapter da = new SqlDataAdapter(cmd);
    da.Fill(dt);

    
}
catch (Exception e)
{

}
return dt;