June 2001
Intermediate to advanced
620 pages
19h 29m
English
Content preview from ADO: ActiveX Data ObjectsBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Asynchronous Execution
Asynchronous execution allows you to execute commands in the background of the client or server, while allowing the application to continue executing other commands. Asynchronous execution is vital when dealing with large data sources over a large network.
In most cases, users will not wait more than a few seconds -- let alone two or three minutes -- for a response from your application indicating that a command is finally done. For instance, suppose an administrator of a large company determines to increase the prices of all items by one dollar. Suppose that this company has 10,000 products. When the user presses a button confirming the price change, she shouldn’t have to wait for all products to be updated before she can continue her work. Instead, once she confirms the price change, the application should issue an asynchronous command to the server to execute the update.
Executing a Command Asynchronously
Before you learn how to execute commands asynchronously, first take a look at a piece of code that takes a significant amount of time to execute:
com.ActiveConnection = "driver={SQL Server}; " _ & "server=JROFF_LAPTOP; " _ & "uid=sa; " _ & "database=Northwind" com.CommandText = "DELETE [Order Details (Backup)]; " sSQL = "INSERT INTO [Order Details (Backup)] " _ & " (OrderID, ProductID, UnitPrice, Quantity, Discount) " _ & "SELECT OrderID, ProductID, UnitPrice, Quantity, Discount " _ & "FROM [Order Details]; " com.CommandText = com.CommandText + sSQL Debug.Print ...Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.