Using the ATL OLE DB Consumer Templates on the Pocket PC - xfgr.com. Implementing a Simple Consumer (OLE DB Templates) Using Bookmarks (OLE DB Templates) Before you open the rowset, you must tell the provider that you want to use bookmarks.
To do this, set the DBPROP_BOOKMARKS property to true in your property set. The provider retrieves bookmarks as column zero, so you must use the special macro BOOKMARK_ENTRY and the CBookmark class if you are using a static accessor. How To ExecuteParameterized Command Multiple Times with ATL OLEDB Consumer Templates. Executing a command multiple times is a very common scenario if the command is a parameterized query.
The way to do "Single Prepare and Multiple Execution" by using ATL OLEDB consumer templates is to call CCommand::Prepare to prepare the command, call CCommand::Open to execute the command, and call CCommand::Close before the next round of execution. The following sample illustrate the major steps in executing a command multiple times. To run this sample, copy and paste the code into a .cpp file and build it as a console project. The sample uses the Authors table in the pubs database of Microsoft SQL Server. Note that you might need to modify the server name and make sure the uid and pwd are correct. Note: What CCommand::Close actually does is close the opened rowset and release the created accessors for the output columns. As an alternative to using consecutive CCommand::Open calls, after CALLING CCcommand::Prepare, you can instead call CCommand::Execute multiple times. To ( ) ( )
Memory Leaks in ATL OLEDB Consumer Objects on CCommand. Introduction The article reveals a very critical bug in the CCommand ATL OLEDB object.
The article explains why it's happening and provides a solution for it. Background Microsoft Knowledge Base describes a well-known memory leak problem and the way to fix it. UDAParts. Asynchronous processing and multiple threads in OLEDB programming. OLE DB Interfaces. Dashboard Get Started Design Develop Test and deploy Certify Sign in OLE DB Interfaces This section of the OLE DB Programmer's Reference contains syntax and semantic information for the OLE DB interfaces.
This topic is a part of: Show: Was this page helpful? Your feedback about this content is important.Let us know what you think. Additional feedback? Thank you! We appreciate your feedback. Centers Related developer sites Other Windows sites Downloads Support Essentials Stay connected © 2014 Microsoft. Performing Asynchronous Operations. Asynchronous Processing (OLE DB) Asynchronous processing enables methods to return immediately without blocking on the calling thread.
Consumers request asynchronous processing when initializing a data source object or when opening or populating a rowset. The consumer must explicitly request asynchronous processing. Otherwise, the provider can perform asynchronous operations in the background but must behave synchronously, blocking if necessary, until the underlying asynchronous operation completes. OLE DB 2.5 providers that support direct URL binding or scoped operations on row objects may also support asynchronous operations. Consumers may request asynchronous processing when binding from a URL to an OLE DB object or when performing scoped operations — such as copy, delete or move — on a row object. Data Source Initialization properties are used when consumers initialize a data source object asynchronously. Asynchronous processing can occur in phases.
Establishing the Connection. EXPRESS OLE DB Library for C++ Environment: : VC++ 6.0, Service Pack 5 Library Class Hierarchy Overview In my last article, I showed how to extend an OLE DB consumer template class and make it much easier to use in applications.
I had also explained how you can utilize the power of C++ exception-handling feature to make your work easier, especially in error handling. It was just a small class in my last article. In this article, I will present a complete library that is feature-rich, light-weight, lightening fast, and most easy to use. When it comes to choosing the right data access technology for application development, most Visual C++ programmers face a puzzling set of choices. Let us try to understand and analyze some of the most obvious data access choices: Native Library : Native libraries are supplied by many database vendors and they provide fastest data access for the respective databases. Since its introduction, ADO has been the most widely used option for data access on Windows platform.
Downloads. How To Insert NULL Data with OLE DB Consumer Templates. OLE DB Programming. OLE DB Consumer Templates (C++) The OLE DB Consumer Templates support the OLE DB version 2.6 specification.
(The OLE DB Consumer Templates are tested against OLE DB 2.6 but do not support every interface in the specification.) The Consumer Templates minimize the amount of code you must write to implement an OLE DB consumer. The templates provide: Easy access to OLE DB features and easy integration with ATL and MFC. An easy binding model for database parameters and columns. OLE DB Consumer Templates Reference. Manages the connection with the data source.
This is a useful class for creating clients because it encapsulates necessary objects (data source and session) and some of the work you need to do when connecting to a data source.