How do I get the textbox value to the database within a repeater?

I have a repeater that I populate from a database:

using (SqlConnection conn = new SqlConnection(connString))
{
   SqlCommand cmd = new SqlCommand(@"SELECT CommunityName, CID, Budget FROM Donation WHERE Year = year(getdate()) ORDER BY CommunityName", conn);
   conn.Open();
   SqlDataAdapter adp = new SqlDataAdapter(cmd);
   DataSet myDataSet = new DataSet();
   adp.Fill(myDataSet);
   myRep.ItemDataBound += new RepeaterItemEventHandler(myRep_ItemDataBound);
   myRep.DataSource = myDataSet;
   myRep.DataBind();
}
void myRep_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
   var textbox = e.Item.FindControl("community");
   textbox.ClientIDMode = ClientIDMode.Static;
   textbox.ID = "community" + (e.Item.ItemIndex + 1);
 }

Repeater:

<asp:UpdatePanel ID="UpdatePanel" runat="server" UpdateMode="Always">
    <ContentTemplate>
       <asp:Repeater ID="myRep" runat="server">
          <ItemTemplate>
             <div class="form-group">
                <asp:Label ID='thisLbl' runat="server" Text='<%# Eval("CommunityName") %>' />
                <asp:TextBox runat="server" ID="community" Text='<%# Eval("Budget") %>' CssClass="form-control" />
             </div>
          </ItemTemplate>
       </asp:Repeater>
    </ContentTemplate>
</asp:UpdatePanel>

This creates 6 textboxes with labels and values, now my question is how do I detect which of these boxes belongs to the record it was initially pulled from in the database? I want to be able to modify the value in these boxes and hit a button to save them back to the database but I can't seem to wrap my head around getting them to the proper records.

Should I set the ID of the textbox to something I can parse through and match with the proper record? In the ItemDataBound?