Update using MySqlDataAdapter doesn't work

问题

I am trying to use MySqlDatAdapter to update a MySql table. But, the table never updates!!! I did this before but with SQL server. Is there anything else that is specific to MySql that I am missing in my code?

        DataTable myTable = new DataTable("testtable");

        MySqlConnection mySqlCon = new MySqlConnection(ConfigurationManager.ConnectionStrings["DBConStr"].ConnectionString);

        MySqlCommand mySqlCmd = new MySqlCommand("SELECT * FROM testtable WHERE Name = 'Tom'");
        mySqlCmd.Connection = mySqlCon;

        MySqlDataAdapter adapter = new MySqlDataAdapter(mySqlCmd);
        MySqlCommandBuilder myCB = new MySqlCommandBuilder(adapter);
        adapter.UpdateCommand = myCB.GetUpdateCommand();

        mySqlCon.Open();

        adapter.Fill(myTable);
        myTable.Rows[0]["Name"] = "Was Tom";
        myTable.AcceptChanges();
        adapter.Update(myTable);
        mySqlCon.Close();

Thanks

回答1:

Remove myTable.AcceptChanges() before the update. Othwerwise that will set all rows RowState to Unchanged, hence the DataAdapter will not know that something was changed.

adapter.Update(myTable) will call AcceptChanges itself after the update is finished.

So...

myTable.Rows[0]["Name"] = "Was Tom";
//myTable.AcceptChanges();
adapter.Update(myTable);

回答2:

My some one need to look into the following solution; In other scenario people may need different solution. Even Don't do any manipulation with Datatable when you Debug at Run-time like this,

myTable.GetChanges(); // Return Any of Chnages Made without applying myTable.Accepchanges()
myTable.GetChanges(DataRowState.Added); // Return added rows without applying myTable.Accepchanges()
myTable.GetChanges(DataRowState.Deleted); 
myTable.GetChanges(DataRowState.Detached);
myTable.GetChanges(DataRowState.Modified);
myTable.GetChanges(DataRowState.Unchanged);

You may get Data According to the above commands. So better try to debug before you pass the datatable to update or insert or delete command.

If myTable.GetChanges() return null then you can SetAdded() or SetModified() back to your DataTable;

foreach(DataRow row in myTable.Rows)
{
  row.SetAdded(); // For Insert Command
  row.SetModified(); // For Update Command
}

来源：https://stackoverflow.com/questions/15259400/update-using-mysqldataadapter-doesnt-work

标签

mysql

dataadapter