Question

基本上我正在尝试开发一个软件，我是编程新手。我试图将文本框的数据插入SQL Server 2008 R2标准，我收到一个错误：

System.NullReferenceException未处理

这是我的代码。

SqlConnection con = new SqlConnection();
con.ConnectionString = "Data Source=(local);Initial Catalog=songs_db;Persist Security Info=True;User ID=sa;Password=iloveyourb";

con.Open();

DataSet ds = new DataSet();

String sql = "Select * From tbl_songdb";

SqlDataAdapter da = new SqlDataAdapter(sql, con);

DataRow drow = ds.Tables["tbl_songdb"].NewRow();  // I am getting error message here.
drow[1] = txt_songName.Text;
drow[2] = txt_minute.Text;
drow[3] = txt_albumnName.Text;
drow[4] = txt_location.Text;

ds.Tables["tbl_songdb"].Rows.Add(drow);
con.Close();

Answer 1

实际上我的数据集是空的，这就是为什么它显示NULL错误

AutoCompleteTextViews

我用这些线来填充它，现在一切正常。感谢所有人给他们的时间。

Answer 2

完全按照错误对你说的做。用try try抓住它：

      try{
    SqlConnection con = new SqlConnection();
            con.ConnectionString = "Data Source=(local);Initial Catalog=songs_db;Persist Security Info=True;User ID=sa;Password=iloveyourb";
            con.Open();
            DataSet ds = new DataSet();
            String sql = "Select * From tbl_songdb";
            SqlDataAdapter da = new SqlDataAdapter(sql, con);
            DataRow drow = ds.Tables["tbl_songdb"].NewRow();  // I am getting error message here.
            drow[1] = txt_songName.Text;
            drow[2] = txt_minute.Text;
            drow[3] = txt_albumnName.Text;
            drow[4] = txt_location.Text;
            ds.Tables["tbl_songdb"].Rows.Add(drow);
        da.Update(ds); 
    con.Close();
    }
    catch(Exception ex)
    {
MessageBox.Show(ex.ToString());

}

Answer 3

SqlConnection con = new SqlConnection();
con.ConnectionString = "Data Source=(local);Initial Catalog=songs_db;Persist Security Info=True;User ID=sa;Password=iloveyourb";

con.Open();

DataSet ds = new DataSet();

String sql = "Select * From tbl_songdb";

SqlDataAdapter da = new SqlDataAdapter(sql, con);
da.Fill(ds);
DataRow drow = ds.Tables[0].NewRow();  // I am getting error message here.
drow[1] = txt_songName.Text;
drow[2] = txt_minute.Text;
drow[3] = txt_albumnName.Text;
drow[4] = txt_location.Text;

ds.Tables[0].Rows.Add(drow);
SQLiteCommandBuilder cmdbuilder = new SQLiteCommandBuilder(da);
da.InsertCommand = cmdbuilder.GetInsertCommand();
da.Update(ds);
ds.AcceptChanges();
con.Close();

与SQL Server数据库连接的错误

3 个答案: