C＃DataAdapter参数错误

Question

Read everything I could, I still can't get my parameter to work with a SqlDataAdapater. If someone can tell me what my problem is it would be much appreciated. I tried to use Parameters.Add first since I've read it is the better method but gave up and tried to use a SqlCommand to no avail.

private void Run_BTN_Click(object sender, EventArgs e)
    {
        var select = "select C.LSTNAME from C " +
                     "inner join bd ON bd.id = C.id " +
                     "@nameParam";
        var c = new SqlConnection(CnnString.CnnVal("DB2"));
        SqlCommand command = new SqlCommand(select, c);
        var dataAdapter = new SqlDataAdapter(command);

        command.Parameters.AddWithValue("@nameParam", "where C.LSTNAME = " + Cust_TB.Text);
       /* dataAdapter.SelectCommand.Parameters.Add(new SqlParameter
        {
              ParameterName = "@nameParam",
              Value = "where C.LSTNAME = " + Cust_TB.Text,
              SqlDbType = SqlDbType.NVarChar,
              Size = 2000  // Assuming a 2000 char size of the field annotation (-1 for MAX)
        }); */

        var ds = new DataSet();
        try
        {
            dataAdapter.Fill(ds);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        Reporting_DGV.ReadOnly = true;
        Reporting_DGV.DataSource = ds;
    }

Answer 1

What? look at your code line below ... you are actually injecting a WHERE clause or SQL statement in your parameter and not a value. SqlParameters are for passing a value to your SQL statement.

command.Parameters.AddWithValue("@nameParam", "where C.LSTNAME = " + Cust_TB.Text);

Your query should be

     var select = "select C.LSTNAME from C inner join bd ON bd.id = C.id where C.LSTNAME = @nameParam";
    var c = new SqlConnection(CnnString.CnnVal("DB2"));
    SqlCommand command = new SqlCommand(select, c);
    command.Parameters.AddWithValue("@nameParam", Cust_TB.Text);
    var dataAdapter = new SqlDataAdapter(command);