Help on DataGrids and DataAdapter with ADO.NET

[FtKarras]

I can NOT update the table, have a DBConcurrency exception.

 

The code I put is a form with a dataGrid filled with the table data of 'categorias' but when I leave the dataGrid to force a DGValidated I always obtain the same exception....

 

... can anyone help me?

 

 

 

public class clsFrmClientes : System.Windows.Forms.Form
{
private System.Windows.Forms.DataGrid dG;
private MySqlDataAdapter myAdapter;
private DataTable myData;

public clsFrmClientes()
{
	InitializeComponent();
	
	myAdapter = new MySqlDataAdapter();
	myData = new DataTable();
	MySqlCommand selCommand = new MySqlCommand();
	string selSQL;
	MySqlCommand updCommand = new MySqlCommand();
	string updSQL;
		

	selSQL = "SELECT * FROM plq.categorias";
	updSQL = "UPDATE plq.categorias SET categoria = @1, descripcion = @2 WHERE cod = @0";
	try {
		// Select Command
		selCommand.Connection = clsGlobal.dbCon;
		selCommand.CommandText = selSQL;

		myAdapter.SelectCommand = selCommand;

		// Update Command
		updCommand.Connection = clsGlobal.dbCon;
		updCommand.CommandText = updSQL;

		MySqlParameter vParam1 = updCommand.Parameters.Add( "@1", MySqlDbType.VarChar, 1 );
		vParam1.SourceColumn = "categoria";
		vParam1.SourceVersion = DataRowVersion.Current;

		MySqlParameter vParam2 = updCommand.Parameters.Add( "@2", MySqlDbType.VarChar, 100 );
		vParam2.SourceVersion = DataRowVersion.Current;
		vParam2.SourceColumn = "descripcion";

		MySqlParameter vParam3 = updCommand.Parameters.Add( "@0", MySqlDbType.VarChar, 5 );
		vParam3.SourceVersion = DataRowVersion.Original;
		vParam3.SourceColumn = "cod";

		myAdapter.UpdateCommand = updCommand;

		myAdapter.Fill(myData);

		dG.DataSource = myData;
	}
	catch ( MySqlException ex )
	{
		MessageBox.Show( "Hay un error leyendo de la base de datos: " + ex.Message );
	}

}
[i]
--> Here comes some Windows Forms Designer code and then...
--> the InitializeComponent() code
[/i]
void DGValidated(object sender, System.EventArgs e)
{
	try {
		myAdapter.Update( myData );
	}
	catch (DBConcurrencyException ex)
	{
		MessageBox.Show( ex.Message );
	}
}
	
}

 

 

... Thanks in advance

Edited August 31, 2005 by FtKarras

[Afraits]

DBConcurrency exception will usually mean that a row has changed in the underlying DB between you populating the grid and trying to update it. Is that scenario possible?

[FtKarras]

I think it is not possible. I am working on my laptop with local DB. There is no other access than mine.

 

I have read in this forum that DBConcurrency raise when there is no row updated too. So I think my problem is at the bind of DataGrid column and table comumns making the UpdateComand parameters returns no row with the WHERE clause (bad @0 parameter???) but I have read my code one hundred times and can't find the problem....

 

I am NEW on dot net

Edited August 31, 2005 by FtKarras

[Machaira]

How about using the CommandBuilder to generate the update command:

myAdapter = new MySqlDataAdapter();
myData = new DataTable();
MySqlCommandBuilder cb;

selSQL = "SELECT * FROM plq.categorias";

try 
{
myAdapter.SelectCommand = new MySqlCommand(selSQL, clsGlobal.dbCon);

cb = new MySqlCommandBuilder(myAdapter);
myAdapter.UpdateCommand = cb.GetUpdateCommand();

myAdapter.Fill(myData);

dG.DataSource = myData;
}

[FtKarras]

Greattttttttt... I didn't know about any MySqlCommandBuilder... it works good

 

Realy thank Machaira