Insert C# data.sqlclient

Question

good afternoon!

I’m starting in C# and I have a question

ja varios tipo de Insert sql server. Ai I’m having difficulty in this part

says: it is not possible to convert from "system.data.sqlclient.sqlparameter"

follows the code:

string strSQL = @"INSERT INTO TESTE (Razão_Social) VALUES ( @parm1 )";
            conn.Open();
            SqlCommand cmd = new SqlCommand (strSQL, conn);
            cmd.Parameters.AddWithValue(@parm1, txt_razao.Text);
            cmd.ExecuteNonQuery();
            conn.Close();



            MessageBox.Show("Cadastrado !!!!");

Answer 1

The method AddWithValue receives two parameters: (string, object), according to the documentation: Addwitvalue

So it must be like this:
cmd.Parameters.AddWithValue("@parm1", txt_razao.Text);

Taking advantage, to help control and close your command object, place your code in a block using, thus:

conn.Open();
string strSQL = @"INSERT INTO TESTE (Razão_Social) VALUES ( @parm1 )";
using(SqlCommand cmd = new SqlCommand(strSQL, conn))
{
   cmd.Parameters.AddWithValue("@parm1", txt_razao.Text);
   cmd.ExecuteNonQuery();
}