Question

I have fetched some data from a SQL database into a datagridview, but after the user modified the data in the datagridview, how can I upload the data back?

And also, I found a code like this:

this.dataGridView1.Update();

What does this method Update? Here is the code where I bind the data to datagridview:

SqlDataReader read;
SqlCommand cmd;
DataTable dt = new DataTable();
cmd = new SqlCommand("Select * from Table", 204.192.49.3);
read = cmd.ExecuteReader();
dt.Load(read);
dataGridView1.DataSource = dt;

Answer 1

The easiest way is to create a temporary DataSet, fill it with data using a SqlDataAdapter and then passing it as dataGridView’s DataSource. This code should do the trick:
DataSet temp = new DataSet();
SqlDataAdapter SDA = new SqlDataAdapter();
SqlCommand command = new SqlCommand();
SqlConnection connection = new SqlConnection();
string connstring = "YourConnectionString";

And then in the method you want to trigger the update do this:

`connection.Open();
 command.CommandText = "SELECT * FROM Table" //Adjust the SQL query to your needs
 command.Connection = connection;
 SDA.SelectCommand = command;
 SDA.Fill(temp);
 dataGridView1.DataSource = temp.Tables[0].DefaultView;`

This should solve your problem.