In most cases one uses one or several datamodules to place db-related
components like IB_Connections, IB_Transactions, Queries etc. on it. If you
will use some events of these components, you have to implement your
eventhandlers directly in the datamodule(s). By placing a
IB_ConnectionSource or IB_TransactionSource on a form, you are able to
implement several eventhandlers diretly in this form. Sometimes (developers)
live gets a little bit easier by doing this.

Robbi