SQL Server数据库连接错误

本文关键字：错误 数据库连接 Server SQL | 更新日期: 2023-09-27 18:03:13

基本上我正在努力开发一个软件，我是新的编程。我试图插入文本框的数据到SQL Server 2008 R2标准，我得到一个错误:

系统。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();

SQL Server数据库连接错误

实际上我的数据集是空的，这就是为什么它显示NULL错误

 da.Fill(ds, "tbl_studentData");

我用这些行来填充它，现在一切都很好。感谢大家的宝贵时间。

完全按照错误告诉你的去做。用try catch像这样处理它:

      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());
}

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();
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