Update the datatable without using DataAdapter.Fill 2 times

Question

I am writing a program to manage a office. (Getting rid of Excels XD).

I have a DAL class with the following variables:

    private MySqlConnection connection;
    private DataSet ds;
    private Hashtable adapters;

There is this method:

    public bool AddTable(string tableName, string sqlStat)
    {
        if (!ds.Tables.Contains(tableName))
        {
            MySqlDataAdapter adapter = new MySqlDataAdapter(sqlStat, connection);
            MySqlCommandBuilder builder = new MySqlCommandBuilder(adapter);
            adapter.InsertCommand = builder.GetInsertCommand();
            adapter.UpdateCommand = builder.GetUpdateCommand();
            adapter.DeleteCommand = builder.GetDeleteCommand();
            adapter.Fill(ds, tableName);
            adapters.Add(tableName, adapter);
            return true;
        }
        return false;
    }

The program will be connected to a server with MySQL database. I need to make sure that when one client changes something in the database another client will see the new data, but this is not happening.

Answer 1

You need to read up on optimistic concurrency, which helps solve the problem of multiple users reading and updating the same data at the same time.

I suggest you start here:

• http://msdn.microsoft.com/en-us/library/aa0416cz%28v=vs.110%29.aspx
• http://www.codeproject.com/Articles/114262/6-ways-of-doing-locking-in-NET-Pessimistic-and-opt