我的整个删除方法（）被成功执行，并且没有错误，但当调试器应用查询线的记录不被删除

Question

表示textBox1.Text.my代码没有数据被以下：

namespace SeparateConnection 
{ 


class clsGridView 
{ 

    Connection co2 = new Connection(); 
    //display our global varaible for connection 
    SqlConnection myconn3 = new SqlConnection("data source=M-SULEMAN-PC;initial catalog=dbmsLogin;integrated security=sspi"); 
    public void Delete() 
    { 
     co2.setconn(); 
     try 
     { 
      DialogResult result = MessageBox.Show("Are you sure you want to delete ?", "Message", 
       MessageBoxButtons.YesNo, MessageBoxIcon.Question); 
      if (result == DialogResult.Yes) 
      { 
       //myconn3.Open(); 
       DataTable table2 = new DataTable(); 
       frmGridView gd = new frmGridView(); 
       SqlDataAdapter myadd2 = new SqlDataAdapter("Delete from tblLogin where UserName ='" + gd.textBox1.Text + "'", myconn3); 
       myadd2.Fill(table2); 

       //Sqlcommandbulider to allow changes to database 
       SqlCommandBuilder mybuild = new SqlCommandBuilder(myadd2); 

       //Update the database 
       myadd2.Update(table2); 

       //Close the connection 
       myconn3.Close(); 

      } 
      else 
       return; 

     } 
     catch (Exception error) 
     { 
      MessageBox.Show(error.ToString()); 
     } 
    } 

----------当我使用相同的类调用和定义method..there是没有问题的

Answer 1

要删除数据，必须遵循这个模式：

SqlCommand cmd = new SqlCommand(); 
cmd.CommandText = "Delete from tblLogin where UserName = @param"; 
cmd.Parameters.Add("@param", gd.textBox1.Text); 
cmd.Connection = conn; 
cmd.ExecuteNonQuery(); 

Answer 2

为什么不试试这样的东西

string connetionString = null; 
      SqlConnection connection ; 
      SqlDataAdapter adapter = new SqlDataAdapter(); 
      string sql = null; 
      connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password"; 
      connection = new SqlConnection(connetionString); 
      sql = "delete product where Product_name ='Product6'"; 
      try 
      { 
       connection.Open(); 
       adapter.DeleteCommand = connection.CreateCommand(); 
       adapter.DeleteCommand.CommandText = sql; 
       adapter.DeleteCommand.ExecuteNonQuery(); 
       MessageBox.Show ("Row(s) deleted !! "); 
      } 
      catch (Exception ex) 
      { 
       MessageBox.Show(ex.ToString()); 
      }