Question

I’m having some difficulties understanding how databases and SQL works. I’m trying to update a certain row in my database. I can remove a row, but when i use the InsertAt function, it is always appended to the end of my database. Also, it’s assigned a new identifier key.

I would like to just edit what is already in there. No need for a new key, and I would like the edited row to stay where it was.

I’ve tried to strip down the code to show the the problem.

public partial class MainWindow : Window
{

    System.Data.SqlClient.SqlConnection con;
    System.Data.SqlClient.SqlDataAdapter da;

    DataSet sessions;

    public MainWindow()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, RoutedEventArgs e)
    {
        con = new System.Data.SqlClient.SqlConnection();

        sessions = new DataSet();

        con.ConnectionString = "Data Source=.\\SQLEXPRESS;AttachDbFilename=C:\\Users\\md\\PokerDataBase.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";

        con.Open();

        string sql = "SELECT * From Sessions";
        da = new System.Data.SqlClient.SqlDataAdapter(sql, con);
        da.Fill(sessions, "Sessions");

        con.Close();

        System.Data.SqlClient.SqlCommandBuilder cb;
        cb = new System.Data.SqlClient.SqlCommandBuilder(da);

        DataTable dt = sessions.Tables["Sessions"];


        DataRow table = sessions.Tables["Sessions"].NewRow();
        table[0] = "Some Data";
        table[1] = "Some Data";
        table[2] = "Some Data";
        table[3] = 2;
        table[4] = 3;
        sessions.Tables["Sessions"].Rows[2].Delete();
        sessions.Tables["Sessions"].Rows.InsertAt(table, 2);

        da.Update(sessions, "Sessions");
    }
}

Could anyone help me figure out what I’m doing wrong?

Answer 1

Error

You are creating a new row using

DataRow table = sessions.Tables["Sessions"].NewRow();

This will add new row to you database, it’s not going to update a row.

Solution

To update a row you need to select that specific row, something like:

DataRow table = sessions.Tables["Sessions"].Rows[0];

then modify the row data and then update da.
This will the update existing row in your database.