Question

I try updating my database after updating the dataset, but evenafter calling the data adapter’s update function the underlying database doesn’t change. I used SqlCommandBuilder and it still wouldn’t update. Once I have the GUI open I can submit and search for values in my dataset but once I close it then re run it, all the changes are gone. Help?

    Code:

        //in my form load event
        con = new System.Data.SqlClient.SqlConnection();
        ds1 = new DataSet();
        ds2 = new DataSet();

        con.ConnectionString = "Data Source=.\\SQLEXPRESS;AttachDbFilename=|DataDirectory|\\Database1.mdf;Integrated Security=True;User Instance=True";

        con.Open();
        MessageBox.Show("Database Open.");

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

        string cust = "SELECT * From tblCustomers";
        da2 = new System.Data.SqlClient.SqlDataAdapter(cust, con);

        da.Fill(ds1, "Purchases");
        numOfRecords = ds1.Tables["Purchases"].Rows.Count;

        da2.Fill(ds2, "Customers");
        numOfCustomers = ds2.Tables["Customers"].Rows.Count;

        con.Close();
        MessageBox.Show("Database Closed.");

    Code:
            //in my submit button click event

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

            System.Data.SqlClient.SqlCommandBuilder cb2;
            cb2 = new System.Data.SqlClient.SqlCommandBuilder(da2);

            DataRow dRow = ds1.Tables["Purchases"].NewRow();
            DataRow dRow2 = ds2.Tables["Customers"].NewRow();

            //dRow updating happens here

            ds1.Tables["Purchases"].Rows.Add(dRow);
            ds2.Tables["Customers"].Rows.Add(dRow2);

            da.Update(ds1, "Purchases");
            da2.Update(ds2, "Customers");

That’s it. There are no error messages, it’s just that even with that, the underlying database doesn’t update and the updates only go as far as the dataset.

Answer 1

The SqlDataAdapter.Update() method returns an integer with the number of rows successfully updated. Consider loading that value into a variable to determine if any rows were reported as updated.

The SqlCommandBuilder likely needs its .GetUpdateCommand() method called. GetUpdateCommand gets the automatically generated SqlCommand object required to perform updates on the database.

cb.GetUpdateCommand();
cb2.GetUpdateCommand();

da.Update(ds1, "Purchases");
da2.Update(ds2, "Customers");

Consider running SQL Server Profiler against your server to determine the TSQL statements that are being generated by the SqlCommand. This will be extremely helpful in determining if the database and statements are as you expect.