delphi 中的 ADO 组件

Question

I am currently using BDE components to connect to a database in Delphi 5 professional version. My problem is that BDE components need BDE Administator to run the application on another machine. So I am planning to buy a new version of Delphi which contains ADO components.

Question: Are ADO components also having issues like the BDE? Do ADO components need any specific setup to run applications on another machine?

Thanks for the help.

Answer 1

All the components have issues in some point, in the case of ADO is very stable, but you can have some specific problems with the providers (like the infamous not support for blob fields in ORACLE using the Microsoft provider) but certainly is more recommendable use ADO instead of the deprecated BDE . About the dependencies, ADO uses providers to connect to the RDBMS, most of them are installed by MDAC (Microsoft Data Access Components) which is included in most of the Windows versions. So in most cases you will not need install any addtional component , at least which you want use a provider not inluded in MDAC like MySql, Firebird or others.

Answer 2

Sounds like if you posted two times the (almost) same question ... with more focus on ADO this time.

As was written in the previous question, if you attempt to connect to an Oracle database using ADO or OleDB, you'll find out that all OleDB providers are buggy for handling Oracle BLOBs: Microsoft's version just do not handle them, and Oracle's version will randomly return null for 1/4 of rows ... So IMHO ADO or OleDB are not a serious option for accessing Oracle database. :(

And if your purpose is to get rid of the BDE installation, you'll find out that the Oracle's OleDB provider is quite huge and that the BDE is much light and better... A standard Oracle's client installation containing the OleDB/ADO provider (which is not installed in the "Light" version of the Oracle's clients), needs a.zip setup of about 660 MB...

On real database data, I found out our Open Source direct access to Oracle to be 2 to 10 times faster than the OleDB provider, without the need to install this provider (nor the BDE). You can even use the Oracle Instant Client provided by Oracle which allows you to run your applications without installing the standard (huge) Oracle client or having an ORACLE_HOME. Just deliver the dll files in the same directory than your application, and it will work.

Of course, this is full Open Source, and works from Delphi 5 up to XE. So when your project may upgrade to a newer Delphi version, it will work. You are not tied to non-Unicode Delphi 5-Delphi 7 version of Oracle components, as you can found on Torry's , eg but those components may help you get rid of the BDE installation for an existing project.

If you don't use BLOBs in your database, you can use ADO. In this case, my advice is to read this post , and use TADODataset , which is available in Delphi 5.

Answer 3

Ok Naren, since you are on Oracle you can use this Oracle driver DOA . We use it exclusively in our Delphi projects.

All our Delphi projects are on Delphi 7 but we are converting all of it to Delphi XE now. When using DOA you do need to install the Oracle client libraries on the client machine. The upside is speed and Oracle support, so the DOA drivers don't need to work on the most common command set like ADO needs to, so the Oracle support is brilliant.