Fetch

Purpose

This demo shows how to fetch paged orders and also master/detail via single server call. See the DA04 article for a discussion on Dynamic Method Binding using this sample as its example.

Getting Started

When you compile and run both projects you will see the client present you with two tabbed pages:

• Paged Orders: when the master dataset ("Orders") is opened, the first 40 records are fetched from the server (assuming that you haven't modified the Max Records Per Fetch setting). Try clicking on the vertical scrollbar. Initially, you will be displaying the other records fetched when the dataset was opened. Once you have reached record 40, another batch of records are then fetched from the server and you can see when this happens because the scrollbar thumb reduces size.
  OrderDetail records are only fetched as required.
• Fetch All: retrieves all orders within the range specified. All associated OrderDetail records are retrieved also.

Examine the Code

The following methods are worth examining:

• GetOrdersAndDetails in FetchService_Impl: called by the Fetch All page and it shows how to retrieve master and detail records in a single server call.
• tbl_PagedOrdersAfterScroll in FetchClientMain: holds the paging logic.